Attempt to install MySQL 5.6 on Travis
Attempt to get past the add-apt-repository command
Try specifying actual package names for MySQL 5.6
Default to keeping the existing configuration files for MySQL
Use new steps for install 5.6
Add dpkg options to use existing configuration
Apparently the new packages install over the old ones
Restart the server properly
Install the MySQL client libraries as well
Move MySQL 5.6 steps to install

This is so Python extensions that use the mysql client libraries can use the new versions.
Release 0.9.3: Attack of the Schema Migrations

3 schema migrations and a few assorted bug fixes, mainly related to MySQL support.