Added the ability to authenticate with Cosmos DB using Azure AD and enable using RBAC; this is optimized for usage with an *adal.ServicePrincipalToken object (#33, #34). See the Cosmos DB documentation for and the example for usage with this library.

Add options to delete methods #25

• API refactoring + features: Query parameters, API bloat reduction, Iterator, More request headers, Performance boost.
• Bug fixes.
• Adding status validators to be able to validate upsert better
• Add license file

Released a new major version after merging #13, since there's a chance for breaking changes for some projects that use this package.