Misc travis-ci build tweaks
Misc travis-ci build tweaks

* Add faraday_middleware gem to address travis-artifacts error:
    /home/travis/.rvm/gems/ruby-1.9.3-p484/gems/faraday-0.9.0.rc7/lib/faraday.rb:189:in `lookup_middleware': :json is not registered on Faraday::Response (Faraday::Error)
* Move gem install to after_success so builds that fail, fail faster
* Make PROJECT_VERSION available to all build stages

sttts/marathon,meln1k/marathon,SivagnanamCiena/marathon,lelezi/marathon,bobrik/marathon,ramitsurana/marathon,IanSaunders/marathon,vivekjuneja/marathon,sttts/marathon,quamilek/marathon,c089/marathon,meln1k/marathon,EvanKrall/marathon,guenter/marathon,janisz/marathon,meln1k/marathon,yp-engineering/marathon,natemurthy/marathon,c089/marathon,HardikDR/marathon,felixb/marathon,janisz/marathon,sielaq/marathon,Caerostris/marathon,hangyan/marathon,guenter/marathon,titosand/marathon,matsluni/marathon,felixb/marathon,Caerostris/marathon,janisz/marathon,sepiroth887/marathon,mesosphere/marathon,ss75710541/marathon,14Zen/marathon,quamilek/marathon,bobrik/marathon,timcharper/marathon,Caerostris/marathon,pgkelley4/marathon,EvanKrall/marathon,mikejihbe/marathon,spacejam/marathon,14Zen/marathon,okuryu/marathon,janisz/marathon,cgvarela/marathon,EasonYi/marathon,guenter/marathon,mesosphere/marathon,pugna0/marathon,airbnb/marathon,murat-lacework/marathon,rtward/marathon,airbnb/marathon,sepiroth887/marathon,c089/marathon,Yhgenomics/marathon,sielaq/marathon,natemurthy/marathon,guenter/marathon,guenter/marathon,EasonYi/marathon,titosand/marathon,MrMarvin/marathon,bobrik/marathon,drewrobb/marathon,rtward/marathon,MiLk/marathon,HardikDR/marathon,MrMarvin/marathon,airbnb/marathon,manojlds/marathon,EasonYi/marathon,IanSaunders/marathon,ayouwei/marathon,lelezi/marathon,mikejihbe/marathon,pugna0/marathon,cgvarela/marathon,felixb/marathon,ramitsurana/marathon,sepiroth887/marathon,sielaq/marathon,EvanKrall/marathon,mesosphere/marathon,drewrobb/marathon,gsantovena/marathon,manojlds/marathon,EvanKrall/marathon,airbnb/marathon,cherrydocker/marathon-1,cgvarela/marathon,ayouwei/marathon,SivagnanamCiena/marathon,gsantovena/marathon,murat-lacework/marathon,sttts/marathon,hangyan/marathon,drewrobb/marathon,meln1k/marathon,MiLk/marathon,bobrik/marathon,mesosphere/marathon,janisz/marathon,natemurthy/marathon,Kosta-Github/marathon,okuryu/marathon,bsideup/marathon,sledigabel/marathon,MiLk/marathon,gsantovena/marathon,mikejihbe/marathon,Yhgenomics/marathon,vivekjuneja/marathon,felixb/marathon,ss75710541/marathon,murat-lacework/marathon,sielaq/marathon,bsideup/marathon,cherrydocker/marathon-1,okuryu/marathon,IanSaunders/marathon,spacejam/marathon,MrMarvin/marathon,spacejam/marathon,ramitsurana/marathon,matsluni/marathon,c089/marathon,vivekjuneja/marathon,timcharper/marathon,Yhgenomics/marathon,14Zen/marathon,HardikDR/marathon,ss75710541/marathon,ayouwei/marathon,lelezi/marathon,bsideup/marathon,yp-engineering/marathon,14Zen/marathon,mesosphere/marathon,pgkelley4/marathon,gsantovena/marathon,Caerostris/marathon,Kosta-Github/marathon,sttts/marathon,gsantovena/marathon,hangyan/marathon,spacejam/marathon,cherrydocker/marathon-1,rtward/marathon,SivagnanamCiena/marathon,drewrobb/marathon,sledigabel/marathon,pugna0/marathon,meln1k/marathon,timcharper/marathon,sledigabel/marathon,manojlds/marathon,matsluni/marathon,quamilek/marathon,Caerostris/marathon