Fully implemented legacy_post with tests.

In bin/TestDancerPluginLegacyRouting:
  Added routes for testing post requests

In t/02-legacy_post.t
  Added Tests for Cases:
    Ensure legacy_post directs to correct controller
    Legacy Route Called Logged when Logging Enabled
    Legacy Route Called NOT Logged when Logging NOT Enabled
    Legacy Route with URI Parameter
    Legacy Route with POST Args