Ghost

* Replace simple-crypt with cryptography for a faster and more common encryption engine.
* Replace the current inheritence implementation with a composition implementation which easily allow to implement additional backends.
* Fix a bug where a stash couldn't be initialized.
* When using the Python API, verify that the `value` field is always a dict.
* Allow to retrieve a value via `stash.get_value(key=key)`
* Raise an error if a stash is initialized twice in the same path
* Change the `--val` flag to `--value`. `--val` is just weird.

* First release of ghost
* Support both TinyDB and SQLAlchemy as supported backends.
* Allow to put, modify, get, delete and list keys.
* Provide encryption via simple-crypt.
* Each key contains the following fields: `description`, `name`, `value`, `created_at`, `modified_at`, `uid` and `metadata`.
* Provide a click based CLI using the TinyDB backend (for now, you can't choose the backend to use when using the CLI. This will be changed later on.)
* When using the CLI, allow to both pretty print and JSON print when retrieving a key.
* Allow to get a