uamqp v0.1.0a3

Release includes some bug fixes as well as new features.

• Added support for asynchronous message receive by iterator or batch.
• Removed synchronous receive iterator, and replaced with synchronous batch receive.
• Added sync and async context managers for Send and Receive Clients.
• Fixed token instability and added put token retry policy.
• Exposed Link ATTACH properties.
• A connection now has a single $cbs session that can be reused between clients.
• Added C debug trace logging to the Python logger (‘uamqp.c_uamqp’)

Installation notes:

• Source install (i.e. using --no-binary) is currently only available for Linux.
• If you are running Mac OSX < 10.13 (High Sierra), please let us know if you encounter any compatibility issues.