Merge branch 'hotfix/1.23.3' into stable
do not show deprecation warning for head ruby, fix #2273
1.23.4
Merge branch 'master' into hotfix/1.23.4
Merge branch 'hotfix/1.23.4'
support the use of additional RVM repositories

This commit adds options for custom domains and repositories to
support the installation of RVM on internal networks that cannot
or should not access the internet directly. Currently, this only
supports bitbucket.org, github.com and github enterprise sites.