Update VERSION to 8.15.0-pre
Update VERSION to 8.15.0-pre

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