Add a helper method to check that gem does not exist in `Gemfile`
Add a helper method to check that gem does not exist in `Gemfile`

MSP-Greg/rails,betesh/rails,untidy-hair/rails,arunagw/rails,betesh/rails,illacceptanything/illacceptanything,assain/rails,yawboakye/rails,schuetzm/rails,kddeisz/rails,baerjam/rails,deraru/rails,fabianoleittes/rails,Vasfed/rails,joonyou/rails,BlakeWilliams/rails,joonyou/rails,Stellenticket/rails,palkan/rails,illacceptanything/illacceptanything,illacceptanything/illacceptanything,yahonda/rails,lcreid/rails,esparta/rails,pvalena/rails,yahonda/rails,Erol/rails,assain/rails,rails/rails,printercu/rails,yalab/rails,jeremy/rails,illacceptanything/illacceptanything,vipulnsward/rails,untidy-hair/rails,tjschuck/rails,palkan/rails,georgeclaghorn/rails,utilum/rails,illacceptanything/illacceptanything,mechanicles/rails,shioyama/rails,kddeisz/rails,deraru/rails,flanger001/rails,illacceptanything/illacceptanything,schuetzm/rails,shioyama/rails,mechanicles/rails,untidy-hair/rails,vipulnsward/rails,Envek/rails,aditya-kapoor/rails,aditya-kapoor/rails,yawboakye/rails,repinel/rails,baerjam/rails,deraru/rails,EmmaB/rails-1,tjschuck/rails,flanger001/rails,rails/rails,jeremy/rails,prathamesh-sonpatki/rails,fabianoleittes/rails,Stellenticket/rails,illacceptanything/illacceptanything,Erol/rails,palkan/rails,printercu/rails,Edouard-chin/rails,yalab/rails,yhirano55/rails,schuetzm/rails,baerjam/rails,lcreid/rails,prathamesh-sonpatki/rails,Edouard-chin/rails,Vasfed/rails,vipulnsward/rails,MSP-Greg/rails,jeremy/rails,rafaelfranca/omg-rails,illacceptanything/illacceptanything,lcreid/rails,notapatch/rails,bogdanvlviv/rails,shioyama/rails,starknx/rails,assain/rails,Vasfed/rails,arunagw/rails,Edouard-chin/rails,yhirano55/rails,illacceptanything/illacceptanything,tgxworld/rails,jeremy/rails,kmcphillips/rails,georgeclaghorn/rails,arunagw/rails,mechanicles/rails,illacceptanything/illacceptanything,bogdanvlviv/rails,iainbeeston/rails,illacceptanything/illacceptanything,kddeisz/rails,kddeisz/rails,betesh/rails,repinel/rails,esparta/rails,BlakeWilliams/rails,notapatch/rails,repinel/rails,kmcphillips/rails,flanger001/rails,yalab/rails,Stellenticket/rails,flanger001/rails,kmcphillips/rails,eileencodes/rails,Stellenticket/rails,utilum/rails,betesh/rails,gauravtiwari/rails,Envek/rails,pvalena/rails,tjschuck/rails,rails/rails,deraru/rails,tgxworld/rails,joonyou/rails,schuetzm/rails,Envek/rails,printercu/rails,illacceptanything/illacceptanything,illacceptanything/illacceptanything,prathamesh-sonpatki/rails,BlakeWilliams/rails,notapatch/rails,mohitnatoo/rails,printercu/rails,mohitnatoo/rails,yawboakye/rails,tjschuck/rails,prathamesh-sonpatki/rails,mohitnatoo/rails,illacceptanything/illacceptanything,starknx/rails,joonyou/rails,MSP-Greg/rails,gauravtiwari/rails,Edouard-chin/rails,bogdanvlviv/rails,mechanicles/rails,arunagw/rails,BlakeWilliams/rails,aditya-kapoor/rails,yahonda/rails,tgxworld/rails,Erol/rails,aditya-kapoor/rails,repinel/rails,rails/rails,starknx/rails,yahonda/rails,baerjam/rails,yawboakye/rails,utilum/rails,iainbeeston/rails,eileencodes/rails,esparta/rails,vipulnsward/rails,shioyama/rails,eileencodes/rails,Envek/rails,fabianoleittes/rails,notapatch/rails,georgeclaghorn/rails,EmmaB/rails-1,untidy-hair/rails,pvalena/rails,gauravtiwari/rails,mohitnatoo/rails,Vasfed/rails,yalab/rails,yhirano55/rails,palkan/rails,fabianoleittes/rails,esparta/rails,lcreid/rails,rafaelfranca/omg-rails,yhirano55/rails,assain/rails,tgxworld/rails,MSP-Greg/rails,bogdanvlviv/rails,utilum/rails,EmmaB/rails-1,georgeclaghorn/rails,pvalena/rails,iainbeeston/rails,iainbeeston/rails,Erol/rails,kmcphillips/rails,illacceptanything/illacceptanything,rafaelfranca/omg-rails,eileencodes/rails