Add more variables to repmgr.conf

We're currently doing a minimal set. Add more (or all options) as attributes to get them controllable through gitlab.rb

/cc @jtevnan

marked this issue as related to #2571

changed title from Add more variabels to repmgr.conf to Add more variables to repmgr.conf

created branch 2712-add-more-variables-to-repmgr-conf

mentioned in merge request !1893 (merged)

mentioned in issue #2522

closed via merge request !1893 (merged)

mentioned in commit fad11d85

mentioned in merge request !1898 (closed)

mentioned in issue #2695 (closed)

mentioned in commit acb2131a