Prepare 2.0 release

[benwebber]

• Merge existing pull requests
• Fix Ansible 2 deprecation warnings
• Drop support for SmartOS
• Adopt SemVer
• Configure test harness for CentOS and Ubuntu
• Stop managing EPEL. We can ask users to configure it themselves (i.e., suggest geerlingguy.epel or add that role in as a dependency.
• Implement Fix the configuration of the webstats ui #35, Only set SSL parameters on bind if needed #39, Support ALPN advertisement in SSL options  #40, and can't get the correct result #43 in ways that are compatible with the new API.

[benwebber]

On further reflection, I think it's wise to clean up and merge the existing PRs (that are backwards compatible) and release a new 1.x version.

We can consider changing the variable contract after that.

Edits marked in bold.

[benwebber]

I have:

• merged all open PRs which 1) are compatible with the 1.x contract and 2) can be merged without intervention.
• tagged v1.1.0 as the last 1.x release (barring bug fixes)
• re-imported the role on Ansible Galaxy

[Sispheor]

Is this role still maintained?