Sqlite3-to-mysql

* [CHORE] update Readme

* [CHORE] fix CI tests
* [CHORE] add linter rules

* [CHORE] refactor package
* [CHORE] test the CLI interface
* [CHORE] fix tests

* [FEAT] add Python 2.7 support
* [CHORE] refactor package
* [CHORE] fix tests
* [CHORE] add option to test against a real SQLite file

* [FIX] catch exceptions
* [FIX] default mysql_string_type from VARCHAR(300) to VARCHAR(255)
* [CHORE] fix CI tests
* [CHORE] option to run tests against a physical MySQL server instance as well as a Docker one
* [CHORE] run tests against any Docker image with a MySQL/MariaDB database
* [CHORE] clean up hanged Docker images with the name "pytest_sqlite3_to_mysql"
* [CHORE] 100% code coverage

* [CHORE] add more tests