Update CHANGELOG for #60
Release 0.2.1

IMPROVEMENTS

* Add pushmaster name to IRC messages (asotille, #63)
* Clean up imports (asotille)
* New submodule-bump tag for requests that include submodule
  changes (jagg81, #60)

DEPRECATED

* l10n and l10n-only tags are no longer used (jagg81, #60)
Merge pull request #68 from Yelp/release-candidate

Release 0.2.1

IMPROVEMENTS

* Add pushmaster name to IRC messages (asotille, #63)
* Clean up imports (asotille)
* New submodule-bump tag for requests that include submodule
  changes (jagg81, #60)

DEPRECATED

* l10n and l10n-only tags are no longer used (jagg81, #60)