Reset the state of StubENV's @env_already_stubbed after each spec run
Reset the state of StubENV's @env_already_stubbed after each spec run

In certain combination of tests, @env_already_stubbed could be set
to `true` even though it never ran for that specific test.

axilleas/gitlabhq,t-zuehlsdorff/gitlabhq,stoplightio/gitlabhq,t-zuehlsdorff/gitlabhq,stoplightio/gitlabhq,mmkassem/gitlabhq,t-zuehlsdorff/gitlabhq,mmkassem/gitlabhq,mmkassem/gitlabhq,iiet/iiet-git,mmkassem/gitlabhq,stoplightio/gitlabhq,dplarson/gitlabhq,iiet/iiet-git,dreampet/gitlab,jirutka/gitlabhq,dplarson/gitlabhq,dreampet/gitlab,t-zuehlsdorff/gitlabhq,axilleas/gitlabhq,jirutka/gitlabhq,jirutka/gitlabhq,stoplightio/gitlabhq,jirutka/gitlabhq,dreampet/gitlab,dplarson/gitlabhq,dreampet/gitlab,axilleas/gitlabhq,dplarson/gitlabhq,iiet/iiet-git,iiet/iiet-git,axilleas/gitlabhq