Add minimum version to the local build git requirement.
Add minimum version to the local build git requirement.

A local build will end up shelling out with `git -C ...`.
This option is introduced in Git 1.8.5:
https://github.com/git/git/commit/44e1e4d67d5148c245db362cc48c3cc6c2ec82ca

Note: This is relevant because the default git package on CentOS 7 is version 1.8.3.

vishnu2kmohan/dcos,jeid64/dcos,surdy/dcos,branden/dcos,GoelDeepak/dcos,surdy/dcos,GoelDeepak/dcos,mesosphere-mergebot/mergebot-test-dcos,vishnu2kmohan/dcos,mesosphere-mergebot/mergebot-test-dcos,BenWhitehead/dcos,lingmann/dcos,mnaboka/dcos,branden/dcos,mesosphere-mergebot/dcos,darkonie/dcos,amitaekbote/dcos,kensipe/dcos,jeid64/dcos,vishnu2kmohan/dcos,lingmann/dcos,dcos/dcos,mnaboka/dcos,mnaboka/dcos,lingmann/dcos,xinxian0458/dcos,mesosphere-mergebot/dcos,darkonie/dcos,vishnu2kmohan/dcos,jeid64/dcos,darkonie/dcos,asridharan/dcos,asridharan/dcos,dcos/dcos,amitaekbote/dcos,mesosphere-mergebot/dcos,mesosphere-mergebot/mergebot-test-dcos,xinxian0458/dcos,kensipe/dcos,mesosphere-mergebot/mergebot-test-dcos,xinxian0458/dcos,mellenburg/dcos,mesosphere-mergebot/dcos,mellenburg/dcos,mellenburg/dcos,branden/dcos,branden/dcos,mellenburg/dcos,mnaboka/dcos,asridharan/dcos,amitaekbote/dcos,dcos/dcos,lingmann/dcos,dcos/dcos,BenWhitehead/dcos,surdy/dcos,mnaboka/dcos,surdy/dcos,darkonie/dcos,kensipe/dcos,darkonie/dcos,GoelDeepak/dcos,asridharan/dcos,kensipe/dcos,BenWhitehead/dcos,GoelDeepak/dcos,amitaekbote/dcos,dcos/dcos,BenWhitehead/dcos,xinxian0458/dcos,jeid64/dcos