Add tests for bin/swift

Tests are written to ensure bin/swift is working properly and using
functions from swiftclient modules as expected.

Change-Id: Idb0581516b7e0a41c97977bb0bb9f8290f67ad13
Makes use of requests.Session

This allows better connection pooling and may improve performances.

Change-Id: I69e986b7387dd3ac281731b8355a3eec34a537f8
Merge "Add tests for bin/swift"