Merge branch 'hotfix/1.21.15'
do not need quotes in math expressions when calculating array size, fix #2057
improve the warning for bundler binstubs hook, closes #2055
Add ruby-2 utf-8 badge
Merge pull request #2070 from elia/patch-1

Add ruby-2 utf-8 badge
update tests - add .ruby-version test, closes #2064
Merge branch 'master' of github.com:wayneeseguin/rvm
issue proper error / warning when compiler missing, update #2071
add a warning for ironruby - it is broken, update #1543
unset GEM_HOME and GEM_HOME before doing any rvm operations from cd hook, fix #2074
add binary rubies for osx, update #2054
extract rubinius directly to target folder, fix #2080
1.21.16
Merge branch 'master' into hotfix/1.21.16
Merge branch 'hotfix/1.21.16' into stable