Bump Travis ruby version to 2.4.1
Bump Travis ruby version to 2.4.1

https://www.ruby-lang.org/en/news/2017/03/22/ruby-2-4-1-released/

illacceptanything/illacceptanything,bogdanvlviv/rails,kddeisz/rails,iainbeeston/rails,flanger001/rails,tjschuck/rails,kmcphillips/rails,yasslab/railsguides.jp,tjschuck/rails,kamipo/rails,arunagw/rails,baerjam/rails,palkan/rails,tgxworld/rails,vipulnsward/rails,eileencodes/rails,yasslab/railsguides.jp,eileencodes/rails,starknx/rails,hanystudy/rails,yawboakye/rails,marklocklear/rails,printercu/rails,BlakeWilliams/rails,palkan/rails,odedniv/rails,mohitnatoo/rails,pvalena/rails,gauravtiwari/rails,felipecvo/rails,gfvcastro/rails,BlakeWilliams/rails,baerjam/rails,samphilipd/rails,lcreid/rails,riseshia/railsguides.kr,mijoharas/rails,esparta/rails,kmcphillips/rails,untidy-hair/rails,ledestin/rails,brchristian/rails,ngpestelos/rails,riseshia/railsguides.kr,prathamesh-sonpatki/rails,vipulnsward/rails,riseshia/railsguides.kr,rafaelfranca/omg-rails,rails/rails,hanystudy/rails,Sen-Zhang/rails,Erol/rails,yalab/rails,baerjam/rails,prathamesh-sonpatki/rails,alecspopa/rails,betesh/rails,Vasfed/rails,kaspth/rails,ttanimichi/rails,palkan/rails,odedniv/rails,assain/rails,tjschuck/rails,MSP-Greg/rails,BlakeWilliams/rails,pvalena/rails,notapatch/rails,lucasmazza/rails,assain/rails,koic/rails,deraru/rails,ttanimichi/rails,kaspth/rails,iainbeeston/rails,esparta/rails,betesh/rails,repinel/rails,yahonda/rails,maicher/rails,EmmaB/rails-1,alecspopa/rails,georgeclaghorn/rails,illacceptanything/illacceptanything,tgxworld/rails,betesh/rails,rossta/rails,illacceptanything/illacceptanything,Edouard-chin/rails,fabianoleittes/rails,mechanicles/rails,esparta/rails,kaspth/rails,yawboakye/rails,marklocklear/rails,gcourtemanche/rails,samphilipd/rails,notapatch/rails,illacceptanything/illacceptanything,lcreid/rails,Envek/rails,mijoharas/rails,jeremy/rails,riseshia/railsguides.kr,travisofthenorth/rails,yhirano55/rails,matrinox/rails,yalab/rails,hanystudy/rails,Stellenticket/rails,yasslab/railsguides.jp,Envek/rails,vipulnsward/rails,yahonda/rails,Stellenticket/rails,aditya-kapoor/rails,utilum/rails,utilum/rails,betesh/rails,lcreid/rails,tgxworld/rails,arunagw/rails,kddeisz/rails,felipecvo/rails,ttanimichi/rails,illacceptanything/illacceptanything,untidy-hair/rails,kddeisz/rails,aditya-kapoor/rails,EmmaB/rails-1,xlymian/rails,flanger001/rails,fabianoleittes/rails,gcourtemanche/rails,schuetzm/rails,yalab/rails,eileencodes/rails,lucasmazza/rails,Erol/rails,jeremy/rails,kamipo/rails,illacceptanything/illacceptanything,baerjam/rails,illacceptanything/illacceptanything,aditya-kapoor/rails,MSP-Greg/rails,shioyama/rails,rossta/rails,yawboakye/rails,samphilipd/rails,kirs/rails-1,illacceptanything/illacceptanything,jeremy/rails,lucasmazza/rails,yhirano55/rails,bradleypriest/rails,iainbeeston/rails,printercu/rails,rafaelfranca/omg-rails,yawboakye/rails,arunagw/rails,arunagw/rails,illacceptanything/illacceptanything,kmcphillips/rails,shioyama/rails,illacceptanything/illacceptanything,deraru/rails,illacceptanything/illacceptanything,matrinox/rails,Sen-Zhang/rails,Stellenticket/rails,palkan/rails,schuetzm/rails,Edouard-chin/rails,koic/rails,deraru/rails,georgeclaghorn/rails,xlymian/rails,MSP-Greg/rails,yahonda/rails,illacceptanything/illacceptanything,BlakeWilliams/rails,joonyou/rails,illacceptanything/illacceptanything,mechanicles/rails,assain/rails,prathamesh-sonpatki/rails,rafaelfranca/omg-rails,mohitnatoo/rails,gauravtiwari/rails,yahonda/rails,joonyou/rails,ledestin/rails,yalab/rails,flanger001/rails,bogdanvlviv/rails,tgxworld/rails,rossta/rails,Edouard-chin/rails,travisofthenorth/rails,mtsmfm/railstest,brchristian/rails,Stellenticket/rails,travisofthenorth/rails,yhirano55/rails,yhirano55/rails,assain/rails,Vasfed/rails,mathieujobin/reduced-rails-for-travis,Envek/rails,aditya-kapoor/rails,notapatch/rails,mohitnatoo/rails,mtsmfm/railstest,brchristian/rails,shioyama/rails,mechanicles/rails,untidy-hair/rails,deraru/rails,mathieujobin/reduced-rails-for-travis,pschambacher/rails,esparta/rails,prathamesh-sonpatki/rails,Edouard-chin/rails,Erol/rails,illacceptanything/illacceptanything,travisofthenorth/rails,MSP-Greg/rails,ngpestelos/rails,pschambacher/rails,bradleypriest/rails,utilum/rails,flanger001/rails,tjschuck/rails,lcreid/rails,schuetzm/rails,mtsmfm/railstest,kirs/rails-1,vipulnsward/rails,gfvcastro/rails,bogdanvlviv/rails,schuetzm/rails,ledestin/rails,kmayer/rails,koic/rails,kirs/rails-1,eileencodes/rails,odedniv/rails,mohitnatoo/rails,Vasfed/rails,fabianoleittes/rails,kmayer/rails,pschambacher/rails,repinel/rails,rails/rails,georgeclaghorn/rails,Erol/rails,Sen-Zhang/rails,mijoharas/rails,pvalena/rails,kddeisz/rails,fabianoleittes/rails,shioyama/rails,mathieujobin/reduced-rails-for-travis,untidy-hair/rails,gfvcastro/rails,Envek/rails,yasslab/railsguides.jp,gfvcastro/rails,utilum/rails,maicher/rails,printercu/rails,rails/rails,starknx/rails,joonyou/rails,jeremy/rails,felipecvo/rails,maicher/rails,repinel/rails,gauravtiwari/rails,rails/rails,xlymian/rails,pvalena/rails,joonyou/rails,illacceptanything/illacceptanything,matrinox/rails,mechanicles/rails,Vasfed/rails,bradleypriest/rails,EmmaB/rails-1,repinel/rails,georgeclaghorn/rails,ngpestelos/rails,kmcphillips/rails,kamipo/rails,notapatch/rails,kmayer/rails,bogdanvlviv/rails,gcourtemanche/rails,alecspopa/rails,marklocklear/rails,printercu/rails,starknx/rails,iainbeeston/rails