Bump plugin version to 5.0.0

Clarified Redmine compatibility in readme.

updated to v3.2.1

Adapts redmine gemavatar to Redmine 3.2

3.1.0

increment internal version to 3.0.7

ran sync_translations

Merge remote-tracking branch 'origin/master'

bump version to 3.0.4

update version to 3.0.3