Schemachange

Added
- Added support for jinja templates. Any file ending .sql or .sql.jinja will be processed using the [Jinja engine](https://jinja.palletsprojects.com/)
- Added a new optional parameter `--modules-folder` to specify where common jinja template, macro or include files reside
- Added new subcommands render and deploy
- The render command can be used to display the final script to the command line.
- The existing functionality moved to a new deploy subcommand
- Fall back behaviour to assume deploy sub command if none provided
- Added reserved variable name `schemachange` and an error will now be raised if supplied by the user via --vars

Changed
- Added check for duplicate filenames. An error will now be generated should two scripts in different folders have the same name. The old behaviour resulted in just the last found script being included for execution.

Changed
- Loosen dependency version constraints
- Fix crash on dry run with no change history table

Added
- Added support for configuring schemachange through a `schemachange-config.yml` YAML file!
- You can now invoke schemachange without supplying any command line arguments if you use the config file
- The filename for the config file is expected to be `schemachange-config.yml`
- Command line arguments override values in the config files
- This also makes it easier to pass variables to your scripts
- For more details please see the [README](README.md) for more details.
- Added a new optional parameter `--config-folder` to specify where your config file resides

Added
- Add Always script type (scripts that begin with the letter 'A'). Always scripts are executed with every run of schemachange

Changed
- Fix repeatable scripts to only execute if there is a change in the script. Repeatable scripts will not be executed with every run anymore!!!
- **IMPORTANT:** If you were relying on the existing behavior, please rename those scripts to start with the letter 'A' (see above)
- Updated versioned script filename parsing logic to use lazy regex matching for splitting version tags
- This addresses a bug with having double underscores (__) in the description

Changed
- Added support for unencrypted private keys
- `SNOWFLAKE_PRIVATE_KEY_PASSPHRASE` environment variable is no longer required if the key is not encrypted

Changed
- Added 'schemachange' as an application parameter when connecting, to enable usage stats.