Context: I run the whole suit of tests and got a loads of:
Fix panic: runtime error: invalid memory address or nil pointer dereference.

The main reason why most of the tests failed was applicaiton limit which is by default set to 2(At most you can have 2 applications).
The error I was presented was "Oops! We encountered an unexpected error.  Please contact support and explain what you were doing at the time this error occurred."
I had to manually fire curl with verbose mode to see the whole response returned by the stormpath.
Thus I decided to extend msg returned by String() method on Error type by developerMessage.

To fix nil pointer dereference test methods that creates applications, directories etc.
will examine the output returned by the SDK and fail accordingly.

Graceful cleanup of tests in case of errors.

Use Stormpath client_credentials grant type

Use new Stormpath API client_credentials OAuth2 grant type instead of
a the current workaround

According to the stormpath's docs this feature is in beta.
One can search the custom data against one of two endpoints
https://docs.stormpath.com/rest/product-guide/latest/reference.html?highlight=expand#custom-data-search

Get account by custom data

We run all go versions in travis in parallel this makes
the test to fail

- Missing social grant type 
- Properly revoke tokens when using bearer auth

Improve API compliance and GoDoc