add tests

[moshe742]

Add tests to make sure all is well and stays that way

[flowgunso]

Have you thought about which test suite to use ? pytest, nose, unittest ?

[moshe742]

Not yet, I think we should start by deciding on how to test and what, after that check which frameworks allow us to do what we want and proceed from there.
For example, when creating the HTML files, do we just check if the file was created? do we want to check it looks as intended?
How can we check the serve command? since it means we need to run a server and check that the user can get a response, but do we check also the actual response (for example, see that the HTML is the same) and if we do, how do we check things that won't change as long as the theme stays the same even if the CSS or HTML tags changed? and so on for all the commands.

[flowgunso]

There are different thing that could be tested. The cli argument's existence, the error raised on invalid data given; the TemplateGenerator's method, the data type returned.