* Throw error on non-string table comment
* add unit tests for all dialects
* removed non-valid comments retyping to ''
* Change dockerode version
* reverted dockerode version locking
* Added support for altering columns
* Add mysql dialect key for alter (modify)
* Added tests for .alter()
* Updated dialects for .alter() on column
* .alter() for mssql and tests
* Added an error for sqlite3 alter column
Sqlite does not support alter column at all
* Implemented schema alter column support for postgresql
* Added unit test for alter column and fixed postgres implementation
* Add test case for adding multiple columns at once (oracle check)
* Try upgrading CI mysql / postgres and distro
* Disabled adding multiple columns test from oracle
* Fixed node 0.12 test compatibility
* Fixed review comments