Add collapsible nav from Bootstrap
Add collapsible nav from Bootstrap

* Switch to jsdeliver.net for assets so all assets come from a single
  CDN and save on multiple DNS lookups.

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