Add a method to clear all registered handlers.

[kilahm]

This is useful as a clean up step at the end of individual unit tests.

I am looking at using your library to mock some server requests, but I would like to ensure that each test has a well defined set of route handlers.

[A]

@kilahm awesome! Can you add few words about clearRoutes to readme?

[A]

ping @kilahm

[kilahm]

Do you have comments for the documentation I added?

[A]

Nope! That's cool :D

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@kilahm published with 0.2.0