Fix setting BasePath and OAuthBasePath in DocuSignClient ctors

[gagyn]

I lost 2 hours investigating why I'm getting USER_AUTHENTICATION_FAILED response. It was happening, because SDK was calling production API, instead of demo, even after providing BaseUrl for Demo to DocuSignClient constructor. 😐

Current version of DocuSign SDK contains bug causing wrong assignment of BasePath while initializing DocuSignClient object. Current workaround is to set api base path using SetBasePath(basePath), but it should be done by constructor, when using overload: public DocuSignClient(string apiBase, string oAuthBase, IWebProxy proxy = null) (line 155).

Also Configuration = new Configuration(apiBase); is useless in every constructor as SetBasePath method always calls it anyway but haven't touched it.

[AppVeyorBot]

AppVeyor build and test pass.

[voltaek]

It would appear that these changes were made as part of v6.1.0. See here in the commit.

[kenharris]

Correct, these changes have been incorporated into a recent release. Closing the PR.