Revert "gitlab shell works if multiple rubies installed"

This reverts commit 533f4cdf30b38c587f7a91f0dfd898b907ecd944.
Use new gitlab-shell v2.3.0

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Merge branch 'fix_tests' into 'master'

Fix tests

See merge request !1262