[AKS] update to v20180331 API and add new feature args

[mboersma]

Uses the new v20180331 AKS API and adds arguments to support new AKS GA and preview features: RBAC, VNet customization ("advanced networking"), no SSH key needed, Log Analytics monitoring, HTTP application routing, and Azure AD integration (in preview).

Note that this still includes a temp commit with a private copy of the azure-mgmt-containerservice .whl. I'll need to remove that when it is published to Pypi, before this PR merges.

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[codecov-io]

Codecov Report

Merging #6497 into rc38 will not change coverage.
The diff coverage is n/a.

@@         Coverage Diff          @@
##           rc38   #6497   +/-   ##
====================================
  Coverage     0%      0%           
====================================
  Files        11      11           
  Lines       133     133           
  Branches      9       9           
====================================
  Misses      133     133

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[troydai]

@mboersma I will put up a do not merge label per the private build. When will the private package be online?

[mboersma]

When will the private package be online?

I'm not sure yet. Azure/azure-sdk-for-python#2186 is ready to go and I'm asking around to get it published.

Edit: available now.

[troydai]

I think the version should be bumped to 2.1.0 as it is GA now?

[troydai]

2.1.0?

[troydai]

Opening an issue to track instead of in code TODO?

[mboersma]

We are already tracking this improvement in VSTS and plan to have it implemented for the subsequent CLI release. I can remove the # TDOO: if you prefer but there are several others in this file too.

[mboersma]

@troydai the .whl is published to pypi and I removed the temp commit. Let me know what other changes you would like to see.

[troydai]

Looks good to me. I'll merge it now.