docs(readme): add clarity on angular requirement
docs(readme): add clarity on angular requirement

* add note strongly recommending the use of Angular 1.3.18 or higher for UI
  Bootstrap 0.13.3 and higher due to animation fixes.

Closes #4277
Closes #4278

cesarmarinhorj/AngularJS-bootstrap,Servoy/bootstrap,DiHuang1986/bootstrap,hyoda/bootstrap,themifycloud/bootstrap,benhalverson/bootstrap,kongx73/bootstrap,pkdevbox/angular-ui-bootstrap,SystemDisc/bootstrap,shiftagent/ui-bootstrap,justin-john/bootstrap-1,finkcloud/bootstrap,icfantv/bootstrap,angular-ui/bootstrap,thalen/bootstrap,vfiles/bootstrap,BookingBug/bootstrap,pmalikbtech/bootstrap,shiftagent/ui-bootstrap,yjukaku/bootstrap,rajesh-frontendengineer/bootstrap-1,stereocilia/bootstrap,looker/bootstrap,yubin-huang/bootstrap,pdsoftplan/bootstrap,guaido79/bootstrap,gato-gordo/bootstrap,Lincoln-xzc/angular-ui-bootstrap,kirning/bootstrap-1,linuxb/bootstrap,thomassorensen/bootstrap,spadgett/bootstrap,KingMario/bootstrap-1,iamcbh/bootstrap,292388900/bootstrap,2363140194/bootstrap,wesleycho/bootstrap,woshiyigebing/bootstrap,Foxandxss/bootstrap,TORO-IO/bootstrap-1,gorork/bootstrap,fabg21/bootstrap,shadowdaw/bootstrap,azahreba/bootstrap,tobigun/bootstrap,davincho/bootstrap,Kpler/bootstrap,davious/angular-ui-bootstrap,lancerushing/bootstrap,Gailby/bootstrap,ksheedlo/bootstrap,karelcallens/bootstrap,eduncan26/bootstrap,gato-gordo/bootstrap,KingMario/bootstrap-1,alokpradhan/bootstrap,oliversalzburg/bootstrap,rhamid/bootstrap-1,byronigoe/bootstrap,franzherzog/bootstrap,bikegriffith/bootstrap,mabi/bootstrap,matteopic/bootstrap,finkcloud/bootstrap,voyagecontrol/bootstrap,kmccaw/bootstrap,nicklv/bootstrap,jordangraft/bootstrap,dsisejkovic/bootstrap,parikmaher534/bootstrap,JDeuker/bootstrap,pkdevbox/bootstrap-1,icfantv/bootstrap,codedogfish/angular-ui-bootstrap,jordangraft/bootstrap,mikesavior/bootstrap,liqingzhu/bootstrap,shihang0001/bootstrap,voyagecontrol/bootstrap,Lincoln-xzc/angular-ui-bootstrap,jaydiablo/bootstrap,nobitagit/bootstrap,infowrap/bootstrap,andrepitombeira/bootstrap,byronigoe/bootstrap,bikegriffith/bootstrap,Anirudhk94/bootstrap,RobJacobs/bootstrap,zhaokunfay/bootstrap,mufl1h/bootstrap,angular-ui/bootstrap,yukisan/bootstrap,rodrigues-daniel/bootstrap,daviesgeek/bootstrap,christor/bootstrap,carlosjunior/bootstrap,rhamid/bootstrap-1,BookingBug/bootstrap,thalen/bootstrap,themifycloud/bootstrap,andrepitombeira/bootstrap,shootermv/bootstrap,mykhaylo-/bootstrap,nlwillia/bootstrap,vfiles/bootstrap,mufl1h/bootstrap,vsternbach/bootstrap,cesarmarinhorj/AngularJS-bootstrap,rodrigues-daniel/bootstrap,zhaokunfay/bootstrap,JDeuker/bootstrap,jackRogers/bootstrap,Gailby/bootstrap,thomassorensen/bootstrap,shadowdaw/bootstrap,lancerushing/bootstrap,tmcgee123/bootstrap,yukisan/bootstrap,Xephi/bootstrap,inoxis91/bootstrap,universsky/bootstrap-1,oliversalzburg/bootstrap,292388900/bootstrap,Nekle/bootstrap,dabos-GFI/angular-ui-bootstrap,Vreasy/bootstrap,matteopic/bootstrap,Zazulei/bootstrap,pireerliu/bootstrap,cgvarela/bootstrap-1,benhalverson/bootstrap,kirning/bootstrap-1,burlhock/bootstrap,ehteshamkafeel/bootstrap,Anirudhk94/bootstrap,mykhaylo-/bootstrap,kongx73/bootstrap,mikesavior/bootstrap,cdrewery/bootstrap,hyoda/bootstrap,rajesh-frontendengineer/bootstrap-1,jackRogers/bootstrap,dabos-GFI/angular-ui-bootstrap,ksheedlo/bootstrap,karelcallens/bootstrap,jaydiablo/bootstrap,mabi/bootstrap,realityking/ui-bootstrap,maoli1110/bootstrap,rasulnz/bootstrap,liiza/bootstrap,tmcgee123/bootstrap,Nekle/bootstrap,kemapak/bootstrap,infowrap/bootstrap,Kpler/bootstrap,davious/angular-ui-bootstrap,shootermv/bootstrap,josheche/bootstrap-1,filso/bootstrap,maoli1110/bootstrap,nobitagit/bootstrap,davincho/bootstrap,suryasingh/bootstrap,Schibum/bootstrap,stereocilia/bootstrap,realityking/ui-bootstrap,filso/bootstrap,nicklv/bootstrap,sullivanpt/bootstrap,benhalverson/bootstrap,xzoth/bootstrap,stanzi83/bootstrap,iamcbh/bootstrap,inukshuk/bootstrap,connyay/bootstrap,parikmaher534/bootstrap,gorork/bootstrap,josheche/bootstrap-1,linuxvom/bootstrap,atulc007/bootstrap-1,fpipita/bootstrap,daviesgeek/bootstrap,shihang0001/bootstrap,rasulnz/bootstrap,franzherzog/bootstrap,nathan-j-brenner/bootstrap-1,caoruiy/bootstrap,DiHuang1986/bootstrap,JonFerrera/ui-bootstrap,atulc007/bootstrap-1,SystemDisc/bootstrap,inoxis91/bootstrap,elancom/bootstrap-1,christor/bootstrap,carlosjunior/bootstrap,edivancamargo/bootstrap,tobigun/bootstrap,dsisejkovic/bootstrap,pdsoftplan/bootstrap,dmc2015/bootstrap,WXwangxin/bootstrap,sullivanpt/bootstrap,kmccaw/bootstrap,dmc2015/bootstrap,SatvikPurohit/bootstrap,yubin-huang/bootstrap,caoruiy/bootstrap,leyanlo/bootstrap,deeg/bootstrap,edivancamargo/bootstrap,burlhock/bootstrap,wesleycho/bootstrap,looker/bootstrap,elancom/bootstrap-1,vsternbach/bootstrap,Bugagazavr/bootstrap,spadgett/bootstrap,pireerliu/bootstrap,stanzi83/bootstrap,kemapak/bootstrap,Xephi/bootstrap,fabg21/bootstrap,alokpradhan/bootstrap,ehteshamkafeel/bootstrap,suryasingh/bootstrap,justin-john/bootstrap-1,fpipita/bootstrap,WXwangxin/bootstrap,Foxandxss/bootstrap,SimilarWeb/bootstrap,nathan-j-brenner/bootstrap-1,JonFerrera/ui-bootstrap,madhudskumar/bootstrap,cgvarela/bootstrap-1,ahsanbagwan/bootstrap,Schibum/bootstrap,SimilarWeb/bootstrap,connyay/bootstrap,pmalikbtech/bootstrap,pkdevbox/bootstrap-1,2363140194/bootstrap,liiza/bootstrap,TORO-IO/bootstrap-1,pkdevbox/angular-ui-bootstrap,GirishKumrawat/bootstrap,SatvikPurohit/bootstrap,Vreasy/bootstrap,leyanlo/bootstrap,azahreba/bootstrap,GirishKumrawat/bootstrap,codedogfish/angular-ui-bootstrap,ahsanbagwan/bootstrap,linuxb/bootstrap,Bugagazavr/bootstrap,yjukaku/bootstrap,madhudskumar/bootstrap,Zazulei/bootstrap,benhalverson/bootstrap,guaido79/bootstrap,linuxvom/bootstrap,eduncan26/bootstrap,cdrewery/bootstrap,inukshuk/bootstrap,deeg/bootstrap,nlwillia/bootstrap,universsky/bootstrap-1,liqingzhu/bootstrap,Servoy/bootstrap,woshiyigebing/bootstrap,xzoth/bootstrap,RobJacobs/bootstrap