Rewrite /roles to Go

[ocket8888]

I'm submitting an ...

improvement request (usability, performance, tech debt, etc.)

Traffic Control components affected ...

• Documentation (possibly)
• Traffic Ops

Current behavior:

/roles is handled by Perl

Expected / new behavior:

/roles should be handled by Go.

Minimum API Version

1.1 - This is the real issue here. The current Go implementation has a minimum version of 1.3

Request Methods

• GET
  (Go added other request methods in API v1.3 - this was the only one in Perl)

Minimal reproduction of the problem with instructions:

N/A