Flask-require

1. Update docs

Docs are now using f strings instead of older style formatting.

2. Add type enforcement

Added type enforcement to the require.fields method.

1. Improved the response function

The response function did not return any other status codes than 200. This has been fixed.

1. Improved the response function

The response function caused some issues with some responses. This has been fixed.

1. Added admin requirement

Added the `admin` requirement to the `flask_require` library.
This requirement assumes that the session variable `admin` is set to `True` if the user is an admin.

2. Added `field` requirement

Added the `field` requirement to the `flask_require` library.
This decorator extracts all function arguments and checks if they are in the JSON `posted` to the server.
If the `field` is not in the JSON, the function will return an error.
If the fields are present in the JSON the fields will be extracted and passed to the function.

3. Added response function

Added the `response` function to the `flask_require` library.
This function is used to create a generic text response to the user.