Keep the `git_source(:github)` override
Keep the `git_source(:github)` override

Bundler 2.0 did not ship with the new git_source settings.

breandan/huginn,brianpetro/huginn,eugenesvk/huginn,dsander/huginn,virtadpt/huginn,strugee/huginn,breandan/huginn,eugenesvk/huginn,dsander/huginn,naiyt/huginn,cantino/huginn,cantino/huginn,naiyt/huginn,gautamkrishnar/huginn,breandan/huginn,naiyt/huginn,virtadpt/huginn,strugee/huginn,strugee/huginn,dsander/huginn,huginn/huginn,brianpetro/huginn,huginn/huginn,huginn/huginn,gautamkrishnar/huginn,brianpetro/huginn,virtadpt/huginn,cantino/huginn,eugenesvk/huginn,gautamkrishnar/huginn