v0.5.0 (#8)

• Revamp WebService using combine chaining + extensions

• Simplify AuthenticatedWebService using the new API

• Prevent token race condition with sync queue

• Use barrier flag for locking the refresh process

• Basic WebService common scenario tests

• Add tests for publisher extension to map http status codes

• Publisher extension tests for decodable stream chains

• Refine WebServiceStreamTests

• Use integer based statusCodes for refresh trigger mechanism

• Finalize AuthenticatedWebService token race tests

• Remove EntwineTests, bump version to 0.5.0