Commented Task: Add Test Cases for All the current methods that does not [1785]

Possibility to Mock<IToken> to get the results we expect instead of directly performing the queries.
Comments: Associated with changeset 34403: Version 0.9.0.0
- Implemented Application Wide Credentials, the application credentials are copied to each thread but any change to a thread or the main thread does not affect the others.
- Resolved bug with Search where the query was not encoded
- Resolved bug with Tweet where the query was not encoded
- Started testing the credentials system