Even more simplification of launch paths in Docker containerizer.
Even more simplification of launch paths in Docker containerizer.

Review: https://reviews.apache.org/r/26615

dforsyth/mesos,abudnik/mesos,gsantovena/mesos,yuquanshan/customizedMesos,jpeach/mesos,andschwa/mesos,zmalik/mesos,andschwa/mesos,asamerh4/mesos,zmalik/mesos,Gilbert88/mesos,neilconway/mesos,verizonlabs/mesos,jpeach/mesos,asamerh4/mesos,kaysoky/mesos,gsantovena/mesos,dforsyth/mesos,asamerh4/mesos,kaysoky/mesos,Gilbert88/mesos,andschwa/mesos,reneploetz/mesos,neilconway/mesos,andschwa/mesos,neilconway/mesos,verizonlabs/mesos,gsantovena/mesos,yuquanshan/customizedMesos,reneploetz/mesos,zmalik/mesos,neilconway/mesos,neilconway/mesos,asamerh4/mesos,abudnik/mesos,Gilbert88/mesos,jpeach/mesos,chhsia0/mesos,gsantovena/mesos,kaysoky/mesos,andschwa/mesos,zmalik/mesos,reneploetz/mesos,dforsyth/mesos,chhsia0/mesos,jpeach/mesos,zmalik/mesos,gsantovena/mesos,craimbert/mesos,jpeach/mesos,yuquanshan/customizedMesos,verizonlabs/mesos,kaysoky/mesos,dforsyth/mesos,kaysoky/mesos,chhsia0/mesos,Gilbert88/mesos,craimbert/mesos,craimbert/mesos,dforsyth/mesos,dforsyth/mesos,gsantovena/mesos,abudnik/mesos,andschwa/mesos,Aman-Jain-14/customizedMesos,chhsia0/mesos,verizonlabs/mesos,Gilbert88/mesos,jpeach/mesos,chhsia0/mesos,Gilbert88/mesos,asamerh4/mesos,craimbert/mesos,dforsyth/mesos,neilconway/mesos,chhsia0/mesos,craimbert/mesos,zmalik/mesos,reneploetz/mesos,craimbert/mesos,abudnik/mesos,andschwa/mesos,reneploetz/mesos,asamerh4/mesos,abudnik/mesos,reneploetz/mesos,chhsia0/mesos,verizonlabs/mesos,gsantovena/mesos,yuquanshan/customizedMesos,Aman-Jain-14/customizedMesos,yuquanshan/customizedMesos,Aman-Jain-14/customizedMesos,zmalik/mesos,neilconway/mesos,Aman-Jain-14/customizedMesos,verizonlabs/mesos,abudnik/mesos,yuquanshan/customizedMesos,kaysoky/mesos,kaysoky/mesos,verizonlabs/mesos,jpeach/mesos,Aman-Jain-14/customizedMesos,Gilbert88/mesos,yuquanshan/customizedMesos,abudnik/mesos,Aman-Jain-14/customizedMesos,asamerh4/mesos,reneploetz/mesos,craimbert/mesos,Aman-Jain-14/customizedMesos