Remove .rvmrc and .ruby-version from version control so we can test with various environments. [#63021844]
Update deprecated gem source. [#63021844]
Fix bad gem URL. [#63021844]
Install and configure Guard. [#63021844]
Ignore temp files. [#63021844]
Remove Gemfile.lock from version control: it shouldn't be there in a gem. [#63021844]
Merge branch 'improve-dev-environment'