fix(buttons): add unit tests for buttons
fix(buttons): add unit tests for buttons

Adds unit tests to buttons, helping bring test coverage to 100%

Closes #3030

alokpradhan/bootstrap,caoruiy/bootstrap,JDeuker/bootstrap,Den-dp/bootstrap,andrepitombeira/bootstrap,eftakharali/bootstrap,Bugagazavr/bootstrap,qpitlove/bootstrap,Anirudhk94/bootstrap,dmc2015/bootstrap,softgrad-dev2/angular_demo,eduncan26/bootstrap,DenisCloutier/bootstrap,freejavaster/bootstrap,ksheedlo/bootstrap,292388900/bootstrap,dmc2015/bootstrap,RobJacobs/bootstrap,matteopic/bootstrap,miiihi/bootstrap,drocbuster/My_AngularJS_Repo,shootermv/bootstrap,eduncan26/bootstrap,ksheedlo/bootstrap,jordangraft/bootstrap,maoli1110/bootstrap,nlwillia/bootstrap,mohuk/bootstrap,MetSystem/bootstrap,obivandamme/bootstrap,chrisirhc/angular-ui-bootstrap,SystemDisc/bootstrap,ljantzen/bootstrap,Marwzoor/bootstrap,Den-dp/bootstrap,connyay/bootstrap,WXwangxin/bootstrap,akinsony/bootstrap,edivancamargo/bootstrap,zepheiryan/bootstrap,Lincoln-xzc/angular-ui-bootstrap,LogicState/bootstrap,pkdevbox/angular-ui-bootstrap,SimilarWeb/bootstrap,pbrewer/bootstrap,nathan-j-brenner/bootstrap-1,ChinnasamyM/bootstrap,corystevens/bootstrap,kmccaw/bootstrap,xiwc/bootstrap-1,mohuk/bootstrap,hxtpoe/bootstrap,filipkis/bootstrap,deeg/bootstrap,realityking/ui-bootstrap,Lohann/bootstrap,fpipita/bootstrap,rasulnz/bootstrap,nicklv/bootstrap,Regencyop/bootstrap,zepheiryan/bootstrap,BookingBug/bootstrap,succ1984/bootstrap,xzoth/bootstrap,linuxvom/bootstrap,JDeuker/bootstrap,BookingBug/bootstrap,KingMario/bootstrap-1,andrepitombeira/bootstrap,shihang0001/bootstrap,thalen/bootstrap,carlosjunior/bootstrap,linuxvom/bootstrap,rgolea/bootstrap,pkdevbox/angular-ui-bootstrap,tmcgee123/bootstrap,carlosjunior/bootstrap,folsom-labs/bootstrap,hyoda/bootstrap,JonathanGawrych/bootstrap,imskojs/bootstrap,finkcloud/bootstrap,bikegriffith/bootstrap,davereed/bootstrap,rainlake/bootstrap,burlhock/bootstrap,bleggett/bootstrap,jaydiablo/bootstrap,rasulnz/bootstrap,andreialecu/bootstrap,universsky/bootstrap-1,mabi/bootstrap,davious/angular-ui-bootstrap,cgat/bootstrap,yong1236/angular-ui-bootstrap,wuwei111467/bootstrap,jaydiablo/bootstrap,Kpler/bootstrap,SatvikPurohit/bootstrap,jackRogers/bootstrap,softgrad-dev2/angular_demo,Crunch-io/bootstrap,filso/bootstrap,azahreba/bootstrap,spadgett/bootstrap,cgat/bootstrap,Servoy/bootstrap,vfiles/bootstrap,DiHuang1986/bootstrap,teng2015/bootstrap,wesleycho/bootstrap,irwinlove/bootstrap-1,benhalverson/bootstrap,cesarmarinhorj/AngularJS-bootstrap,bleggett/bootstrap,minzen/bootstrap,infowrap/bootstrap,lancerushing/bootstrap,xiwc/bootstrap-1,ccslakey/bootstrap,martin-brennan-csnet/bootstrap,yonglehou/bootstrap-1,AlexFine/bootstrap,nobitagit/bootstrap,bqevin/bootstrap-1,MikhailNazarov/bootstrap,sandeepkaturi/report-manage-of-bootstrap,byronigoe/bootstrap,filso/bootstrap,Schibum/bootstrap,Lexxville/bootstrap-1,rhamid/bootstrap-1,davious/angular-ui-bootstrap,josheche/bootstrap-1,vsternbach/bootstrap,cgvarela/bootstrap-1,guaido79/bootstrap,mufl1h/bootstrap,stereocilia/bootstrap,rajesh-frontendengineer/bootstrap-1,yjukaku/bootstrap,thomassorensen/bootstrap,Lincoln-xzc/angular-ui-bootstrap,WXwangxin/bootstrap,benhalverson/bootstrap,pbrewer/bootstrap,Schibum/bootstrap,Lalem001/angular-ui-bootstrap,parikmaher534/bootstrap,Jchavez/bootstrap-1,Gailby/bootstrap,oliversalzburg/bootstrap,hyoda/bootstrap,pmalikbtech/bootstrap,akinsony/bootstrap,tobigun/bootstrap,liqingzhu/bootstrap,miiihi/bootstrap,wuwei111467/bootstrap,SystemDisc/bootstrap,gorork/bootstrap,justin-john/bootstrap-1,TORO-IO/bootstrap-1,karelcallens/bootstrap,universsky/bootstrap-1,xzoth/bootstrap,dabos-GFI/angular-ui-bootstrap,noellejung/bootstrap,kemapak/bootstrap,Gailby/bootstrap,Foxandxss/bootstrap,hxtpoe/bootstrap,TORO-IO/bootstrap-1,themifycloud/bootstrap,buchslava/bootstrap,inoxis91/bootstrap,rajesh-frontendengineer/bootstrap-1,qrohlf/bootstrap,qrohlf/bootstrap,pmalikbtech/bootstrap,drocbuster/My_AngularJS_Repo,tobigun/bootstrap,qpitlove/bootstrap,dgoncalves1/bootstrap,matteopic/bootstrap,Xephi/bootstrap,wuhoujun/bootstrap,SimilarWeb/bootstrap,mabi/bootstrap,madhudskumar/bootstrap,techkrish/bootstrap,saputro-dwy/bootstrap,bikegriffith/bootstrap,dgoncalves1/bootstrap,vlajos/bootstrap,iamcbh/bootstrap,reiniergs/bootstrap,Regencyop/bootstrap,atulc007/bootstrap-1,guaerguagua/bootstrap,icfantv/bootstrap,madhudskumar/bootstrap,codedogfish/angular-ui-bootstrap,folsom-labs/bootstrap,lancerushing/bootstrap,tmcgee123/bootstrap,gfaceless/bootstrap,imskojs/bootstrap,blighli/bootstrap,teng2015/bootstrap,ahsanbagwan/bootstrap,mikesavior/bootstrap,birdy-/bootstrap,filipkis/bootstrap,parikmaher534/bootstrap,JonathanGawrych/bootstrap,Emobe/bootstrap,eftakharali/bootstrap,Lexxville/bootstrap-1,ljantzen/bootstrap,ThePenguin1140/semantic-angular,rhamid/bootstrap-1,stanzi83/bootstrap,blighli/bootstrap,martin-brennan-csnet/bootstrap,inukshuk/bootstrap,rodrigues-daniel/bootstrap,saputro-dwy/bootstrap,elijah513/bootstrap,elijah513/bootstrap,kongx73/bootstrap,woshiyigebing/bootstrap,liqingzhu/bootstrap,pdsoftplan/bootstrap,Emobe/bootstrap,andreialecu/bootstrap,Anirudhk94/bootstrap,VoltiSubito/bootstrap,LogicState/bootstrap,Zazulei/bootstrap,fernando-sendMail/bootstrap,yubin-huang/bootstrap,yangcwGIT/bootstrap,shadowdaw/bootstrap,saintnikopol/bootstrap,yukisan/bootstrap,themifycloud/bootstrap,shiftagent/ui-bootstrap,ehteshamkafeel/bootstrap,Vreasy/bootstrap,sullivanpt/bootstrap,christor/bootstrap,fernando-sendMail/bootstrap,cdrewery/bootstrap,minzen/bootstrap,fjg1989/bootstrap,thomassorensen/bootstrap,wuhoujun/bootstrap,JonFerrera/ui-bootstrap,jackRogers/bootstrap,ehteshamkafeel/bootstrap,MetSystem/bootstrap,stereocilia/bootstrap,davincho/bootstrap,mykhaylo-/bootstrap,suryasingh/bootstrap,looker/bootstrap,guaerguagua/bootstrap,linuxb/bootstrap,Vreasy/bootstrap,woshiyigebing/bootstrap,iamcbh/bootstrap,liiza/bootstrap,nathan-j-brenner/bootstrap-1,nicklv/bootstrap,vsternbach/bootstrap,Jchavez/bootstrap-1,Foxandxss/bootstrap,SandeepSikhakolli/bootstrap,dsisejkovic/bootstrap,reinisp/bootstrap,wesleycho/bootstrap,guaido79/bootstrap,DiHuang1986/bootstrap,kmccaw/bootstrap,mykhaylo-/bootstrap,AlexFine/bootstrap,sullivanpt/bootstrap,benhalverson/bootstrap,zhaokunfay/bootstrap,krossoverintelligence/bootstrap,Nekle/bootstrap,deeg/bootstrap,JonFerrera/ui-bootstrap,bqevin/bootstrap-1,karelcallens/bootstrap,MikhailNazarov/bootstrap,succ1984/bootstrap,RobJacobs/bootstrap,reinisp/bootstrap,linuxb/bootstrap,mufl1h/bootstrap,kemapak/bootstrap,cgvarela/bootstrap-1,fabg21/bootstrap,fjg1989/bootstrap,birdy-/bootstrap,gato-gordo/bootstrap,Bugagazavr/bootstrap,netanelgilad/bootstrap-1,justin-john/bootstrap-1,looker/bootstrap,pdsoftplan/bootstrap,suryasingh/bootstrap,nobitagit/bootstrap,gbasto/bootstrap,Marwzoor/bootstrap,Lohann/bootstrap,corystevens/bootstrap,jczerwinski/bootstrap-1,franzherzog/bootstrap,fmccown/bootstrap,SandeepSikhakolli/bootstrap,liiza/bootstrap,kirning/bootstrap-1,nlwillia/bootstrap,KingMario/bootstrap-1,fpipita/bootstrap,oliversalzburg/bootstrap,reiniergs/bootstrap,benhalverson/bootstrap,buchslava/bootstrap,fabg21/bootstrap,shihang0001/bootstrap,shootermv/bootstrap,DenisCloutier/bootstrap,christor/bootstrap,shiftagent/ui-bootstrap,gfaceless/bootstrap,alokpradhan/bootstrap,angular-ui/bootstrap,Xephi/bootstrap,leyanlo/bootstrap,edivancamargo/bootstrap,Lalem001/angular-ui-bootstrap,292388900/bootstrap,jczerwinski/bootstrap-1,rodrigues-daniel/bootstrap,chrisirhc/angular-ui-bootstrap,gato-gordo/bootstrap,Real-Currents/ui-bootstrap,spadgett/bootstrap,Servoy/bootstrap,vlajos/bootstrap,kirning/bootstrap-1,yjukaku/bootstrap,obivandamme/bootstrap,codedogfish/angular-ui-bootstrap,sandeepkaturi/report-manage-of-bootstrap,zhaokunfay/bootstrap,cesarmarinhorj/AngularJS-bootstrap,davincho/bootstrap,realityking/ui-bootstrap,Zazulei/bootstrap,yong1236/angular-ui-bootstrap,bsiddiqui/bootstrap,burlhock/bootstrap,pkdevbox/bootstrap-1,maoli1110/bootstrap,GirishKumrawat/bootstrap,gorork/bootstrap,techkrish/bootstrap,daviesgeek/bootstrap,dsisejkovic/bootstrap,leyanlo/bootstrap,rgolea/bootstrap,Crunch-io/bootstrap,pireerliu/bootstrap,inoxis91/bootstrap,azahreba/bootstrap,pkdevbox/bootstrap-1,netanelgilad/bootstrap-1,angular-ui/bootstrap,GirishKumrawat/bootstrap,bsiddiqui/bootstrap,josheche/bootstrap-1,yubin-huang/bootstrap,ahsanbagwan/bootstrap,krossoverintelligence/bootstrap,elancom/bootstrap-1,byronigoe/bootstrap,Farael49/bootstrap,stanzi83/bootstrap,yonglehou/bootstrap-1,gbasto/bootstrap,fmccown/bootstrap,kongx73/bootstrap,infowrap/bootstrap,2363140194/bootstrap,noellejung/bootstrap,inukshuk/bootstrap,rainlake/bootstrap,mikesavior/bootstrap,caoruiy/bootstrap,yukisan/bootstrap,franzherzog/bootstrap,jordangraft/bootstrap,Real-Currents/ui-bootstrap,dabos-GFI/angular-ui-bootstrap,freejavaster/bootstrap,VoltiSubito/bootstrap,Kpler/bootstrap,davereed/bootstrap,vfiles/bootstrap,irwinlove/bootstrap-1,ccslakey/bootstrap,atulc007/bootstrap-1,shadowdaw/bootstrap,elancom/bootstrap-1,pireerliu/bootstrap,finkcloud/bootstrap,daviesgeek/bootstrap,cdrewery/bootstrap,Nekle/bootstrap,icfantv/bootstrap,Farael49/bootstrap,thalen/bootstrap,ThePenguin1140/semantic-angular,2363140194/bootstrap,saintnikopol/bootstrap,yangcwGIT/bootstrap,voyagecontrol/bootstrap,voyagecontrol/bootstrap,SatvikPurohit/bootstrap,connyay/bootstrap,ChinnasamyM/bootstrap