README: Add PyPI badge
README: Add PyPI badge

Fixes https://github.com/coala-analyzer/coala/issues/763

aptrishu/coala,MattAllmendinger/coala,damngamerz/coala,yashLadha/coala,NalinG/coala,CruiseDevice/coala,andreimacavei/coala,Nosferatul/coala,tltuan/coala,netman92/coala,d6e/coala,NalinG/coala,sudheesh001/coala,scottbelden/coala,sophiavanvalkenburg/coala,NiklasMM/coala,FeodorFitsner/coala,jayvdb/coala,scriptnull/coala,yland/coala,RJ722/coala,Uran198/coala,netman92/coala,NalinG/coala,FeodorFitsner/coala,coala/coala,stevemontana1980/coala,sils1297/coala,kartikeys98/coala,arush0311/coala,Tanmay28/coala,shreyans800755/coala,kartikeys98/coala,mr-karan/coala,MariosPanag/coala,incorrectusername/coala,rimacone/testing2,sophiavanvalkenburg/coala,ayushin78/coala,meetmangukiya/coala,ManjiriBirajdar/coala,meetmangukiya/coala,sophiavanvalkenburg/coala,lonewolf07/coala,CruiseDevice/coala,vinc456/coala,scottbelden/coala,andreimacavei/coala,swatilodha/coala,djkonro/coala,rresol/coala,mr-karan/coala,AbdealiJK/coala,aptrishu/coala,AbdealiJK/coala,yashtrivedi96/coala,MattAllmendinger/coala,MariosPanag/coala,incorrectusername/coala,Nosferatul/coala,Uran198/coala,djkonro/coala,meetmangukiya/coala,scriptnull/coala,MariosPanag/coala,nemaniarjun/coala,rimacone/testing2,SambitAcharya/coala,AdeshAtole/coala,ManjiriBirajdar/coala,arush0311/coala,netman92/coala,arafsheikh/coala,arafsheikh/coala,tltuan/coala,nemaniarjun/coala,Tanmay28/coala,lonewolf07/coala,refeed/coala,refeed/coala,Asalle/coala,stevemontana1980/coala,FeodorFitsner/coala,karansingh1559/coala,Shade5/coala,sils1297/coala,sudheesh001/coala,jayvdb/coala,saurabhiiit/coala,MattAllmendinger/coala,arjunsinghy96/coala,dagdaggo/coala,JohnS-01/coala,AdeshAtole/coala,tushar-rishav/coala,dagdaggo/coala,karansingh1559/coala,sagark123/coala,NiklasMM/coala,kartikeys98/coala,impmihai/coala,saurabhiiit/coala,saurabhiiit/coala,d6e/coala,mr-karan/coala,abhiroyg/coala,svsn2117/coala,AbdealiJK/coala,SambitAcharya/coala,yland/coala,svsn2117/coala,scriptnull/coala,Uran198/coala,SambitAcharya/coala,Asalle/coala,shreyans800755/coala,tltuan/coala,Balaji2198/coala,SanketDG/coala,coala-analyzer/coala,vinc456/coala,rimacone/testing2,arafsheikh/coala,Asnelchristian/coala,Tanmay28/coala,arjunsinghy96/coala,Balaji2198/coala,swatilodha/coala,RJ722/coala,RJ722/coala,yashtrivedi96/coala,Asalle/coala,svsn2117/coala,scottbelden/coala,SambitAcharya/coala,damngamerz/coala,NalinG/coala,Shade5/coala,arjunsinghy96/coala,coala-analyzer/coala,scriptnull/coala,swatilodha/coala,CruiseDevice/coala,Shade5/coala,Tanmay28/coala,damngamerz/coala,impmihai/coala,yashLadha/coala,SambitAcharya/coala,sagark123/coala,scriptnull/coala,rresol/coala,Tanmay28/coala,dagdaggo/coala,Balaji2198/coala,stevemontana1980/coala,aptrishu/coala,lonewolf07/coala,AdeshAtole/coala,rresol/coala,vinc456/coala,sagark123/coala,incorrectusername/coala,coala-analyzer/coala,djkonro/coala,refeed/coala,ManjiriBirajdar/coala,impmihai/coala,JohnS-01/coala,Tanmay28/coala,yashtrivedi96/coala,sudheesh001/coala,ayushin78/coala,tushar-rishav/coala,nemaniarjun/coala,coala/coala,shreyans800755/coala,SambitAcharya/coala,Asnelchristian/coala,scriptnull/coala,yashLadha/coala,coala/coala,Asnelchristian/coala,karansingh1559/coala,d6e/coala,tushar-rishav/coala,ayushin78/coala,jayvdb/coala,abhiroyg/coala,arush0311/coala,NalinG/coala,Tanmay28/coala,SanketDG/coala,Tanmay28/coala,SambitAcharya/coala,sils1297/coala,andreimacavei/coala,NiklasMM/coala,scriptnull/coala,NalinG/coala,NalinG/coala,JohnS-01/coala,SanketDG/coala,abhiroyg/coala,yland/coala,Nosferatul/coala