A few enhancements to gh-pages

- Fixed navbar toggle button (you could't see it in mobile mode cause it 's white just like the background)
- Added `.vagrant` and `.DS_Store` to `.gitignore`
- Added a `Vagrantfile` that will install Ruby and Jekyll
- Updated Bootstap from `v3.0.1` to `v3.1.0`
Merge pull request #106 from Ilyes512/gh-pages

A few enhancements to gh-pages