Remove unused mixins from pipelines feature specs
Remove unused mixins from pipelines feature specs

darkrasid/gitlabhq,stoplightio/gitlabhq,openwide-java/gitlabhq,openwide-java/gitlabhq,iiet/iiet-git,axilleas/gitlabhq,mmkassem/gitlabhq,dreampet/gitlab,dreampet/gitlab,LUMC/gitlabhq,mmkassem/gitlabhq,t-zuehlsdorff/gitlabhq,stoplightio/gitlabhq,jirutka/gitlabhq,LUMC/gitlabhq,stoplightio/gitlabhq,iiet/iiet-git,dreampet/gitlab,dplarson/gitlabhq,t-zuehlsdorff/gitlabhq,htve/GitlabForChinese,iiet/iiet-git,LUMC/gitlabhq,htve/GitlabForChinese,jirutka/gitlabhq,darkrasid/gitlabhq,axilleas/gitlabhq,openwide-java/gitlabhq,axilleas/gitlabhq,mmkassem/gitlabhq,darkrasid/gitlabhq,mmkassem/gitlabhq,jirutka/gitlabhq,openwide-java/gitlabhq,dreampet/gitlab,axilleas/gitlabhq,iiet/iiet-git,LUMC/gitlabhq,t-zuehlsdorff/gitlabhq,stoplightio/gitlabhq,htve/GitlabForChinese,dplarson/gitlabhq,dplarson/gitlabhq,darkrasid/gitlabhq,jirutka/gitlabhq,dplarson/gitlabhq,htve/GitlabForChinese,t-zuehlsdorff/gitlabhq