No way to pass tgt_type to API

[jheiselman]

Pepper version: 0.7.6
Salt Master version: 3001+ds-2 installed via pkg repo on Ubuntu 16.04
Salt API version is the same

There does not appear to be a way to use the Pepper class to pass along a tgt_type. Passing in the expr_form argument to .local() appears to put it in the expr_form attribute on the JSON dictionary instead of the tgt_type attribute.

This has an empty return as it isn't matching properly

saltapi.local(grain, "service.status", [someservice], expr_form='grain')
{}

This works

payload = {
  'client': 'local',
  'tgt': grain,
  'tgt_type': 'grain',
  'fun': 'service.status',
  arg: [someservice]
}
saltapi.low(payload)
<<< Returns expected data >>>

[timwsuqld]

Seems #186 should fix this when it's merged