Merge pull request travis-ci#486 from travis-ci/ag-bump-version

Bump version to 1.8.8

Version 1.8.6

Bump to v1.8.4

Fix addressable for old Ruby versions

A dependency of addressable named public_suffix is not compatible
with Ruby < 2.0.

Bump to version 1.8.2

Update to version 1.8.1

tag v1.8.0

tag v1.7.7

tag v1.7.6