Increased version to 0.7.1.dev2 after release of 0.7.1.dev1.

(commit by unleash 0.5.8.dev1)
Added tox and travis testing configurations.
Removed unused import of Mock.
Added PEP8 testing.
Added new testing structure based on py.test.
Reworked new testing structure, closer to old one.
Ported over id-gen tests.
Ported tests for FilesystemStore.
Removed DictStore tests from old test tree.
Removed old testing baseclass.
Moved hashfunc out of idgen.
Tests for HMAC functionality.
Migrated cache testing.
Added --doctest-modules.
Removed doctests from old test suite.
Ported redis tests.
Better redis tests.
Dropped google-appengine tests.
Ported memcache tests.
Added redis-server and memcached services to travis.