Replace assertEqual(None, *) with assertIsNone in tests
Replace assertEqual(None, *) with assertIsNone in tests

Replace assertEqual(None, *) with assertIsNone in tests to have
more clear messages in case of failure.

Change-Id: Ia3889bf5122589dbfee311d2c783aa889b2c8cbc
Closes-bug: #1280522

swiftstack/swift3-stackforge,swiftstack/swift3-stackforge,stackforge/swift3,stackforge/swift3