update Ruby required version in Getting Started guide [ci skip]
update Ruby required version in Getting Started guide [ci skip]

mohitnatoo/rails,yasslab/railsguides.jp,bradleypriest/rails,illacceptanything/illacceptanything,Sen-Zhang/rails,vipulnsward/rails,gfvcastro/rails,ledestin/rails,illacceptanything/illacceptanything,Stellenticket/rails,sealocal/rails,xlymian/rails,Sen-Zhang/rails,arjes/rails,georgeclaghorn/rails,fabianoleittes/rails,alecspopa/rails,vipulnsward/rails,voray/rails,elfassy/rails,kddeisz/rails,kachick/rails,pvalena/rails,shioyama/rails,EmmaB/rails-1,yahonda/rails,untidy-hair/rails,Spin42/rails,ngpestelos/rails,tjschuck/rails,gauravtiwari/rails,felipecvo/rails,rails/rails,hanystudy/rails,shioyama/rails,MSP-Greg/rails,kenta-s/rails,joonyou/rails,shioyama/rails,esparta/rails,starknx/rails,iainbeeston/rails,hanystudy/rails,iainbeeston/rails,Edouard-chin/rails,ledestin/rails,odedniv/rails,voray/rails,odedniv/rails,utilum/rails,shioyama/rails,maicher/rails,schuetzm/rails,vassilevsky/rails,rossta/rails,betesh/rails,pschambacher/rails,pschambacher/rails,yhirano55/rails,pschambacher/rails,alecspopa/rails,gavingmiller/rails,sergey-alekseev/rails,mechanicles/rails,rails/rails,Erol/rails,palkan/rails,stefanmb/rails,samphilipd/rails,palkan/rails,odedniv/rails,tjschuck/rails,Vasfed/rails,yhirano55/rails,Erol/rails,joonyou/rails,schuetzm/rails,illacceptanything/illacceptanything,baerjam/rails,assain/rails,mijoharas/rails,arunagw/rails,rafaelfranca/omg-rails,MichaelSp/rails,baerjam/rails,prathamesh-sonpatki/rails,arunagw/rails,lcreid/rails,ttanimichi/rails,notapatch/rails,joonyou/rails,yawboakye/rails,yasslab/railsguides.jp,jeremy/rails,felipecvo/rails,Spin42/rails,deraru/rails,yhirano55/rails,kamipo/rails,matrinox/rails,rails/rails,stefanmb/rails,rafaelfranca/omg-rails,esparta/rails,kaspth/rails,matrinox/rails,illacceptanything/illacceptanything,tijwelch/rails,eileencodes/rails,sergey-alekseev/rails,bolek/rails,kenta-s/rails,Vasfed/rails,iainbeeston/rails,travisofthenorth/rails,travisofthenorth/rails,tijwelch/rails,notapatch/rails,yalab/rails,rbhitchcock/rails,repinel/rails,maicher/rails,untidy-hair/rails,yawboakye/rails,kamipo/rails,travisofthenorth/rails,ngpestelos/rails,Vasfed/rails,mechanicles/rails,matrinox/rails,kmcphillips/rails,jeremy/rails,repinel/rails,starknx/rails,richseviora/rails,rafaelfranca/omg-rails,xlymian/rails,bradleypriest/rails,yahonda/rails,fabianoleittes/rails,BlakeWilliams/rails,georgeclaghorn/rails,kmayer/rails,gauravtiwari/rails,Vasfed/rails,arjes/rails,yalab/rails,rossta/rails,kddeisz/rails,illacceptanything/illacceptanything,lucasmazza/rails,mtsmfm/railstest,lcreid/rails,utilum/rails,pvalena/rails,aditya-kapoor/rails,mtsmfm/railstest,riseshia/railsguides.kr,sealocal/rails,xlymian/rails,mathieujobin/reduced-rails-for-travis,rossta/rails,travisofthenorth/rails,esparta/rails,pvalena/rails,mohitnatoo/rails,eileencodes/rails,ttanimichi/rails,kddeisz/rails,printercu/rails,amoody2108/TechForJustice,lcreid/rails,yasslab/railsguides.jp,88rabbit/newRails,printercu/rails,kenta-s/rails,kmayer/rails,richseviora/rails,deraru/rails,ngpestelos/rails,stefanmb/rails,mtsmfm/railstest,mtsmfm/rails,mechanicles/rails,yahonda/rails,georgeclaghorn/rails,kaspth/rails,baerjam/rails,mijoharas/rails,marklocklear/rails,bogdanvlviv/rails,MSP-Greg/rails,deraru/rails,tjschuck/rails,yhirano55/rails,gcourtemanche/rails,printercu/rails,prathamesh-sonpatki/rails,utilum/rails,arunagw/rails,Edouard-chin/rails,gfvcastro/rails,untidy-hair/rails,iainbeeston/rails,arjes/rails,joonyou/rails,georgeclaghorn/rails,kaspth/rails,arunagw/rails,MichaelSp/rails,kmcphillips/rails,Edouard-chin/rails,betesh/rails,mtsmfm/rails,tgxworld/rails,flanger001/rails,pvalena/rails,rails/rails,lcreid/rails,prathamesh-sonpatki/rails,amoody2108/TechForJustice,kmcphillips/rails,Spin42/rails,assain/rails,illacceptanything/illacceptanything,sergey-alekseev/rails,lucasmazza/rails,esparta/rails,aditya-kapoor/rails,illacceptanything/illacceptanything,palkan/rails,EmmaB/rails-1,rbhitchcock/rails,bradleypriest/rails,koic/rails,marklocklear/rails,yalab/rails,yasslab/railsguides.jp,gauravtiwari/rails,repinel/rails,gcourtemanche/rails,coreyward/rails,kirs/rails-1,illacceptanything/illacceptanything,vassilevsky/rails,MichaelSp/rails,gcourtemanche/rails,baerjam/rails,flanger001/rails,brchristian/rails,mechanicles/rails,EmmaB/rails-1,maicher/rails,mohitnatoo/rails,mtsmfm/rails,kachick/rails,eileencodes/rails,bolek/rails,kirs/rails-1,flanger001/rails,Envek/rails,vassilevsky/rails,yawboakye/rails,Edouard-chin/rails,tgxworld/rails,illacceptanything/illacceptanything,kachick/rails,marklocklear/rails,printercu/rails,starknx/rails,betesh/rails,ttanimichi/rails,mohitnatoo/rails,fabianoleittes/rails,illacceptanything/illacceptanything,illacceptanything/illacceptanything,bogdanvlviv/rails,betesh/rails,hanystudy/rails,notapatch/rails,riseshia/railsguides.kr,yawboakye/rails,fabianoleittes/rails,samphilipd/rails,illacceptanything/illacceptanything,yahonda/rails,brchristian/rails,kirs/rails-1,Stellenticket/rails,elfassy/rails,notapatch/rails,palkan/rails,88rabbit/newRails,Stellenticket/rails,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