Prepare release 5.2.1 (ruflin#1323)

* Update changelog
* Lint php files

Prepare release-5.2.0 (ruflin#1286)

* Update liniting

Enable travis on the 5.1-php55 branch (ruflin#1259)

The .travis.yml file currently limits travis to only
running on the master branch. Update to include the
new branch supporting php 5.5 as well.

Fix make doc (ruflin#1244)

Prepare 5.0.0 release (ruflin#1230)

Prepare release 5.0.0-beta1 (ruflin#1212)

Release 3.2.3 (ruflin#1177)

* Prepare 3.2.3 release
* Run `make lint`
* Update CHANGELOG.md
* Update elasticsearch dependency to 2.4.0

Preparting 3.2.2 release (ruflin#1165)

Prepare Release 3.2.1 (ruflin#1100)

Prepare Elastica Release 3.2.0 (ruflin#1085)