feat(reporter.junit): add a 'skipped' tag for skipped testcases
feat(reporter.junit): add a 'skipped' tag for skipped testcases

Closes #321

machuga/karma,unional/karma,SamuelMarks/karma,czchen/karma,joakimkarlsson/karma,SamuelMarks/karma,dannycroft/karma,pedrotcaraujo/karma,mprobst/karma,xiaoking/karma,shakyShane/karma,sylvain-hamel/karma,jfroom/karma,czchen/karma,skycocker/karma,clbond/karma,gayancliyanage/karma,astorije/karma,Dignifiedquire/karma,skycocker/karma,powerkid/karma,IsaacChapman/karma,timols/karma,thirtyseven/karma,growlybear/karma,chhsiao1981/testacular,harme199497/karma,IveWong/karma,jsdir/karma,jmendiara/karma,thomasboyt/karma,gayancliyanage/karma,vojtajina/karma,robdodson/karma,Klaudit/karma,youprofit/karma,xiaoking/karma,johan/karma,dotfold/testacular,robdodson/karma,lencioni/karma,tomkuk/karma,karma-runner/karma,nmalaguti/karma,harme199497/karma,behzad88/karma,powerkid/karma,astorije/karma,makeusabrew/karma,jankopriva/karma,codedogfish/karma,IsaacChapman/karma,swayf/karma,wesleycho/karma,jfroom/karma,bitwiseman/karma,Klaudit/karma,wesleycho/karma,Grummle/karma,xiaoking/karma,jankopriva/karma,youprofit/karma,astorije/karma,gfxmonk/karma,ashtuchkin/testacular,codedogfish/karma,karma-runner/karma,hitesh97/karma,remy/karma,johnjbarton/karma,marcodejongh/karma,iammerrick/karma,ryanflorence/testacular,hitesh97/karma,jamestalmage/karma,simudream/karma,sja/karma,david-garcia-nete/karma,switchfly/karma,panrafal/karma,simudream/karma,IveWong/karma,simudream/karma,marthinus-engelbrecht/karma,mccalltd/karma,jeffjewiss/karma,Basemm/karma,ashaffer/karma,karma-runner/karma,thomasboyt/karma,toranb/karma,xdissent/karma,davidmichaelkarr/karma,tschaub/karma,kahwee/karma,drkibitz/karma,aiboy/karma,chhsiao1981/testacular,sublimino/karma,igorlima/karma,KidkArolis/karma,aiboy/karma,wilkerlucio/karma,peteryates/karma,Dignifiedquire/karma,ajoslin/karma,chrisirhc/karma,johnjbarton/karma,chrisirhc/karma,WickyNilliams/karma,kjbekkelund/karma,davidmichaelkarr/karma,mpj/testacular,jan-molak/karma,mprobst/karma,pmq20/karma,lgalfaso/karma,rhlass/karma,patrickporto/karma,david-garcia-nete/karma,jjoos/karma,muffs/karma,stevemao/karma,makeusabrew/karma,rylnd/karma,andersjanmyr/karma,matti/karma,sergeylukin/karma,jamestalmage/karma,rgaskill/karma,KrekkieD/karma,viruschidai/karma,adamnation/karma,eddiemonge/karma,clbond/karma,skycocker/karma,rhlass/karma,brianmhunt/karma,Klaudit/karma,drkibitz/karma,WickyNilliams/karma,hppycoder/karma,sublimino/karma,adamnation/karma,jsdir/karma,Basemm/karma,hppycoder/karma,viruschidai/karma,eddiemonge/karma,jbdeboer/karma,hleeldc/karma,dmitriiabramov/karma,youprofit/karma,ashaffer/karma,r3mi/karma,dmitriiabramov/karma,marthinus-engelbrecht/karma,nmalaguti/karma,pmq20/karma,tschaub/karma,NimaVaziri/karma,hindsightsoftware/karma,xdissent/karma,jamestalmage/karma,unional/karma,ajoslin/karma,oyiptong/karma,geddski/karma,buley/karma,iammerrick/karma,oyiptong/karma,karma-runner/karma,markoa/karma,rhlass/karma,shirish87/karma,KrekkieD/karma,growlybear/karma,ck1125/karma,ernsheong/karma,hindsightsoftware/karma,rgaskill/karma,IveWong/karma,geddski/karma,oyiptong/karma,behzad88/karma,ck1125/karma,IsaacChapman/karma,hexelon/karma,vtsvang/karma,kahwee/karma,brenoc/karma,clbond/karma,garcimouche/karma,shakyShane/karma,zheller/karma,marthinus-engelbrecht/karma,timebackzhou/karma,kjbekkelund/karma,buley/karma,youprofit/karma,yandex-lego/karma,Sanjo/karma,rageshkrishna/karma,andersjanmyr/karma,amagee/karma,vojtajina/karma,buley/karma,astorije/karma,KrekkieD/karma,zheller/karma,mprobst/karma,rageshkrishna/karma,pmq20/karma,wilkerlucio/karma,dotfold/testacular,bertrandgressier/karma,behzad88/karma,dannycroft/karma,ashtuchkin/testacular,gfxmonk/karma,maksimr/karma,johnjbarton/karma,Demeterr/karma,peteryates/karma,OniOni/karma,jeffjewiss/karma,mpj/testacular,NimaVaziri/karma,OniOni/karma,jeffjewiss/karma,tomkuk/karma,markoa/karma,gdi2290/karma,david-garcia-nete/karma,panrafal/karma,stevemao/karma,ashtuchkin/testacular,Demeterr/karma,aiboy/karma,rhlass/karma,oyiptong/karma,wesleycho/karma,ernsheong/karma,rgaskill/karma,codedogfish/karma,gdi2290/karma,vtsvang/karma,gayancliyanage/karma,Sanjo/karma,maksimr/karma,lencioni/karma,tomkuk/karma,aiboy/karma,fredrikbonander/karma,brianmhunt/karma,simudream/karma,chrisirhc/karma,kahwee/karma,garcimouche/karma,brianmhunt/karma,jjoos/karma,stevemao/karma,fivetanley/karma,patrickporto/karma,wesleycho/karma,powerkid/karma,thirtyseven/karma,timebackzhou/karma,fredrikbonander/karma,ijobling/karma,igorlima/karma,hitesh97/karma,vtsvang/karma,pedrosnk/karma,yandex-lego/karma,Klaudit/karma,nmalaguti/karma,codedogfish/karma,IsaacChapman/karma,shirish87/karma,xiaoking/karma,brenoc/karma,pedrotcaraujo/karma,bitwiseman/karma,timebackzhou/karma,lencioni/karma,sylvain-hamel/karma,mccalltd/karma,switchfly/karma,johnjbarton/karma,muffs/karma,revolunet/karma,IveWong/karma,machuga/karma,panrafal/karma,toranb/karma,sylvain-hamel/karma,patrickporto/karma,adamnation/karma,SamuelMarks/karma,sja/karma,brianmhunt/karma,pedrosnk/karma,fivetanley/karma,pavelgj/testacular,pmq20/karma,kahwee/karma,cironunes/karma,timebackzhou/karma,jmendiara/karma,sergeylukin/karma,unional/karma,jacopotarantino/karma,pedrotcaraujo/karma,hleeldc/karma,hexelon/karma,bitwiseman/karma,vojtajina/karma,Grummle/karma,jacopotarantino/karma,cironunes/karma,tomkuk/karma,powerkid/karma,patrickporto/karma,harme199497/karma,pavelgj/testacular,stevemao/karma,agrublev/karma,johan/karma,shirish87/karma,hitesh97/karma,ryanflorence/testacular,Dignifiedquire/karma,revolunet/karma,mpj/testacular,jan-molak/karma,jjoos/karma,rageshkrishna/karma,KidkArolis/karma,joakimkarlsson/karma,skycocker/karma,clbond/karma,jjoos/karma,Dignifiedquire/karma,amagee/karma,lgalfaso/karma,pedrosnk/karma,matti/karma,ijobling/karma,pedrotcaraujo/karma,Sanjo/karma,marcodejongh/karma,growlybear/karma,jbdeboer/karma,KrekkieD/karma,ernsheong/karma,swayf/karma,Sanjo/karma,bertrandgressier/karma,vtsvang/karma,ijobling/karma,r3mi/karma,gayancliyanage/karma,remy/karma,rylnd/karma,nmalaguti/karma,marthinus-engelbrecht/karma,maksimr/karma,yandex-lego/karma,jsdir/karma,unional/karma,harme199497/karma,timols/karma,chrisirhc/karma,dmitriiabramov/karma,agrublev/karma,buley/karma,jamestalmage/karma