Add Unit Testing GitHub CI

[smt5541]

Primarily: Adds Unit Tests for most cases I could think of
Additionally: Fixes a few bugs I found along the way:

• Minumum string length does not work #37
• v: int = Query(func) custom validation function would receive str values
• v: Union[bool, int] = Query() would fail because int values cannot have .lower() called on them
• v: List[str] = Query() custom validation function would receive individual str values instead of the whole list
• Negative int values were not accepted by Route parameters due to upstream behavior in Flask. Applied the Query parsing of str values to Route to allow paths of /<v> to be received correctly by a v: int = Route() parameter
• v: FileStorage = File(min_length=300) would fail when it shouldn't when using the Flask built-in dev server

[Ge0rg3]

Closing as changes included in #40 👍