Optional authorization parameters

[patrickkusebauch]

Optional authorization URL creation parameter in vain of Oauth2 to be appended to the URL. No change in case you don't use it, if you do, you can add parameters to the authorization URL.

Resolves #130

[bencorlett]

Thank you for this MR :)

Could you please add a test to verify this functionality?

The tests in v1 are a bit of a shambles. In v2 they are much better. But perhaps, could you please add another test similar to this one but with additional parameters?

Also, as a nitpick, could you call the second argument $parameters or $additionalParameters - I feel $options is a little vague in this scenario.

Thank you again! :)

[patrickkusebauch]

@bencorlett I have added the test. The reason I called it options is to keep consistency with the OAuth2 library where the same parameter is also called options. Calling it anything else would bring additional complexity IMHO.

[bencorlett]

Thank you again, looks great. I accept the justification of naming the parameter as $options too :)