use standard gitlab namespace regex for group name validation
use standard gitlab namespace regex for group name validation

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