(PDB-904) Switch fact_values.value_string trgm index to be GIN not GIST

There were reports of crashing due to a bug in pg_trgm indexing when a large
fact value was loaded into PuppetDB.

This patch removes the old index via migration, and will then replace it with
the index handling mechanism.

Signed-off-by: Ken Barber <ken@bob.sh>
Merge pull request #1106 from kbarber/ticket/stable/pdb-904-switch-large-trgm-index-to-use-gin

(PDB-904) Switch fact_values.value_string trgm index to be GIN not GIST
(PDB-13) Add wheezy to PDB acceptance tests

This PR adds a wheezy image to our acceptance tests.
Merge pull request #1098 from wkalt/ticket/master/pdb-13-add-wheezy-acceptance-test

(PDB-13) Add wheezy to PDB acceptance tests
Merge branch 'stable'

* stable:
  (PDB-13) Add wheezy to PDB acceptance tests
  (PDB-904) Switch fact_values.value_string trgm index to be GIN not GIST
(PDB-489) return producer timestamp

This exposes our "producer-timestamp" field on the factsets and catalogs
endpoints.  On factsets the field is queryable and orderable. The next step
will be to push the generation of this field back to the agent.
Merge pull request #1113 from wkalt/ticket/master/pdb-489-return-producer-timestamp

(PDB-489) return producer timestamp