Remove dependence on ActiveSupport/Rails

- define logger and logfile in PtOscMigration
- refactor some functionality from execute_pt_osc into migrate_table and execute_sql_for_table
- fixed bug when no tables are set to be commanded
- add tests
- bump version to 0.0.5
  - update CHANGELOG
Merge pull request #4 from steverice/remove-activesupport-dependency

Remove dependence on ActiveSupport/Rails