d6336563e5
Summary: I have updated the Vagrantfile to have an entry for CentOS 7. Also created a simple build script which is pretty similar to the one in Beringei. How to test: ``` vagrant up centos7 ``` Todo: Implement -j X for the build. Closes https://github.com/facebook/rocksdb/pull/3530 Differential Revision: D7090739 Pulled By: ajkr fbshipit-source-id: 9f9eda5b507568993543d08de7ce168dfc12282e