Fabfed-py

What's Changed
* Stitching GCP with AWS via Fabric
* Stitching Chameleon with Cloudlab via Fabric
* Updated stitching policy details for aws and gcp facilities due AL2S changes.
* Removed support for networks referring to nodes
* Restructured examples and updated documentation.
* Bgp secret is no longer hardcode d and is tied to a session
* Configurable bandwidth for networks
* Asynchronous support in the core classes
* cleaned up jupyter examples and add/tested example for supplying policy by abessiari in https://github.com/fabric-testbed/fabfed/pull/152


**Full Changelog**: https://github.com/fabric-testbed/fabfed/compare/1.8...1.9

What's Changed

* Stitching GCP with AWS via Fabric
* Stitching Chameleon with Cloudlab via Fabric
* Updated stitching policy details for aws and gcp facilities due AL2S changes.
* Removed support for networks referring to nodes
* Restructured examples and updated documentation.
* Bgp secret is no longer hardcode d and is tied to a session
* Configurable bandwidth for networks
* Asynchronous support in the core classes

**Full Changelog**: https://github.com/fabric-testbed/fabfed/compare/1.8...1.9a

Main Changes
* Updating versions of ansible modules
* Nodes use the attribute `network` when they depend on a network across all providers
* Nodes will be added to fabnet v4 if they don't depend on a network.
* Allow users to be to select a vlan for chameleon networks.
* Vlans for clouldlab will be selected randomly. Users can still specify a vlan if desired.

What's Changed
* Update gcp_utils.py by zlion in https://github.com/fabric-testbed/fabfed/pull/130
* Janus updates by abessiari in https://github.com/fabric-testbed/fabfed/pull/133
* Hotfix lzhang9 by zlion in https://github.com/fabric-testbed/fabfed/pull/132
* node will only be added to public fabnet if not added to a fabfed (stitch) net… by abessiari in https://github.com/fabric-testbed/fabfed/pull/134
* Janus updates by disprosium8 in https://github.com/fabric-testbed/fabfed/pull/136
* handling adding the nodes for cloud when using not using interface at… by abessiari in https://github.com/fabric-testbed/fabfed/pull/137


**Full Changelog**: https://github.com/fabric-testbed/fabfed/compare/1.7b...1.8

rel1.5-beta
This release features the workflow definition, workflow session tools and stitching policy handling.