Remove redundant hard coded replication parameters

The following new `mysql` class replication parameters were added in 0.8.0, however the existing hard coded parameters were not removed from the my.conf.erb template:

- `expire_logs_days`
- `max_binlog_size`
Merge branch 'remove-redundant-parameter' of github.com:3flex/puppetlabs-mysql into remove-redundant-parameter