Declarative application specifications for Fission (#422)

This change enables users to have declarative specifications for Fission resources. Users can specify their "app" in a set of spec files, and use a new fission CLI command to "apply" these specs to a running cluster.

The new "spec" CLI also includes archiving of local source files, and a file watcher that re-builds archives and uploads them on file changes, and a package build watcher that waits for package builds on the CLI. 

A "--spec" option is also added to "function create", and will be added to other resources in future changes.  This option causes a YAML to be outputted to the specs directory instead of the resource being created on the cluster.

The CLI "fission spec --help" outputs usage information.

glide.lock

@@ -1,5 +1,5 @@
-hash: 7c938e591b0602b9fd3412aeffd3f1438fc77eaea80c8d9dd03431adb0e1e1c9
-updated: 2017-12-13T16:13:45.935783+08:00
+hash: 93c80adbba10750a7fca4536f93880f152527a8f04eedf40a8ea8cbadeb88779
+updated: 2017-12-02T21:38:02.116016618-08:00
 imports:
 - name: cloud.google.com/go
   version: 3b1ae45394a234c385be014e9a488f2bb6eef821
@@ -46,6 +46,8 @@ imports:
   - log
 - name: github.com/emicklei/go-restful-swagger12
   version: dcef7f55730566d41eae5db10e7d6981829720f6
+- name: github.com/fsnotify/fsnotify
+  version: 4da3e2cfbabc9f751898f250b49f2439785783a1
 - name: github.com/ghodss/yaml
   version: 73d445a93680fa1a78ae23a5839bad48f32ba1ee
 - name: github.com/go-openapi/analysis
@@ -134,6 +136,8 @@ imports:
   version: a0006b13c722f7f12368c00a3d3c2ae8a999a0c6
   subpackages:
   - xxHash32
+- name: github.com/pkg/errors
+  version: f15c970de5b76fac0b59abb32d62c17cc7bed265
 - name: github.com/PuerkitoBio/purell
   version: 8a290539e2e8629dbc4e6bad948158f790ec31f4
 - name: github.com/PuerkitoBio/urlesc