Tilefile watches for changes in ytt templates

- When using `local()` in the Tiltfile it will not know
  to watch those files for changes, so each time we use
  `local()` we now also use `watch_file()`
- As a result, editing a ytt template file now causes
  an immediate `kubectl apply` of the results

hack/lib/tilt/Tiltfile

@@ -24,6 +24,8 @@ local_resource(
 
 # Render the Dex installation manifest using ytt.
 k8s_yaml(local(['ytt','--file', '../../../test/deploy/dex']))
+# Tell tilt to watch all of those files for changes.
+watch_file('../../../test/deploy/dex')
 
 # Collect all the deployed Dex resources under a "dex" resource tab.
 k8s_resource(
@@ -54,6 +56,8 @@ k8s_yaml(local([
     '--data-value', 'image_repo=image/local-user-auth',
     '--data-value', 'image_tag=tilt-dev',
 ]))
+# Tell tilt to watch all of those files for changes.
+watch_file('../../../deploy/local-user-authenticator')
 
 # Collect all the deployed local-user-authenticator resources under a "local-user-auth" resource tab.
 k8s_resource(
@@ -91,6 +95,8 @@ k8s_yaml(local([
     '--data-value-yaml', 'replicas=1',
     '--data-value-yaml', 'service_nodeport_port=31234',
 ]))
+# Tell tilt to watch all of those files for changes.
+watch_file('../../../deploy/supervisor')
 
 # Collect all the deployed supervisor resources under a "supervisor" resource tab.
 k8s_resource(
@@ -131,6 +137,8 @@ k8s_yaml(local([
     '--data-value discovery_url=$(TERM=dumb kubectl cluster-info | awk \'/Kubernetes master/ {print $NF}\') ' +
     '--data-value-yaml replicas=1',
 ]))
+# Tell tilt to watch all of those files for changes.
+watch_file('../../../deploy/concierge')
 
 # Collect all the deployed local-user-authenticator resources under a "concierge" resource tab.
 k8s_resource(