[fix] Stub out app stager before each model test

  This change fixes commit bd0f315 to effectively disable
AppStager#delete_droplet to avoid running in an unexpected
(un-configured) state.

  Test plan: all unit tests passed.

Change-Id: I45f1e975e515d067a698c0e7a3b4b871b98e7ef8
after_modify hook for model api

  This change adds a after_modify hook which is called after update and
association changes.

Change-Id: I61cb9889ea88ea00310ac2b8efaa27de7a461cd6
dea_update_pending? on app objects

  This change makes app objects carry a dirty state when the associated
routes change. This can be used to make a decision whether the DEA's
need to be updated.

Change-Id: I7bcdfaec24fc83a03d4df4291af7caeb4340e99c
Update DEA when an app's associated routes change

  CC updates the DEA when we add or remove routes for a running app.
  Updates are coalesced so as to reduce message bus traffic.

  Test plan: all unit tests passed.

Change-Id: I9f2403d8d167bc957af60f13251df27c05c4a2e2
Update DEA when a route's associated apps change

  CC updates the DEA when we add or remove running apps for a route.
  This change puts the dea update logic in the model. This coupling is a
bit too tight and we might want to move it out using an event emitter.

  Test plan: all unit tests passed.

Change-Id: I8933e505bf9fa2286e9dad534913332986368876
send old style svc label-version to stager

Change-Id: Ic45d1fd64e16d6a0a125c3457de5d52e74e8c6c9
Fix styling.

Change-Id: I34e245d1b46464ef173f21bebdb5083d67b83c58
In files API, send path to DEA via NATS.

- Accept responses from DEA v2 in file_uri_v2 field in NATS response.
- Add / change unit tests.

Change-Id: I0596a9854aad3f5b1d452ed33b8c22355c5ebebb
Replace credentials with tuple.

Change-Id: I6b2f67263d51b96ab104761ee7c7f3fc1d899d9e
Fix styling.

Change-Id: I97ca48302d28ed77538af6bfc37157a9d866e8b6
include uaa token in security context

* provide an explicit .clear method on the security context
* provide an explict .set for the security context that includes an optional uaa
token
* remove the old direct set of the user object

Change-Id: I29f9e31b3af7ab7f9173f76a920e8a6254efd5e1
legacy users api

Note, we want to get out of the business of lookup by email since we no longer
know them.  However, BVTs/Yeti currently rely on the ability to at least look
up yourself.

Change-Id: I39b5e88222720700f2d6b3c54fa0c43bca119c73
legacy get /services/:name

Change-Id: I653538bcbeafbaef0b0249792dbbd0dd88059897
support creation of N users for parallel yeti.

Outputs a yaml snippet to copy into your .bvt/config file.

Pin and Alex will do proper support for this in cf and yeti, but this will tide
us over in the mean time.

Change-Id: Ia7da848e54f9588a9512bc534089e936defd7bad
add metadata to app model

Change-Id: I0542d252592e8c609985e194f65292beaa333b20
add command= to app model

This sets the command in the metadata.

Change-Id: I294e1bd49d838fa0c3b6f4d7c36ece174d337056
import command for apps and export metadata

Change-Id: If9bb3891ccad68f341f3a4657d80100ea3b26a10
send app metadata to stager

Change-Id: Ifade7ed928ce167d1720e9d3210f82d0d9512d82
legacy app api stand alone command support

Change-Id: I0ac340868eee6aa7fa79b96520d29033b9e5c3ca
remove metadata from v2 api

elements will go at the top level in v2, and metadata will be used internally.
We might want to purge it from the db altogether and schematize these fields,
and just generate it for the stager/dea, but we can revisit that.

Change-Id: I62eba507548937f87dfa0f47b8f6236a079d9a14