Remove committed vendored dependencies

Unfortunately this broke the `go get` consumers so backing it out.
Enable travis caching of the dep cache to help CI instability.

.gitignore

@@ -27,3 +27,6 @@ _testmain.go
 *.swp
 *~
 .DS_Store
+
+# ignore vendor/
+vendor/

.travis.yml

@@ -13,8 +13,15 @@ branches:
 
 env:
   global:
+    - DEP_RELEASE_TAG=v0.5.1 # so the script knows which version to use
     - IGNORE_BREAKING_CHANGES=true
 
+before_install:
+  - curl -sSL https://raw.githubusercontent.com/golang/dep/master/install.sh | sh
+
+install:
+  - dep ensure -v
+
 script:
   - bash rungas.sh
   - grep -L -r --include *.go --exclude-dir vendor -P "Copyright (\d{4}|\(c\)) Microsoft" ./ | tee /dev/stderr | test -z "$(< /dev/stdin)"
@@ -25,3 +32,7 @@ script:
   - go run ./tools/apidiff/main.go packages ./services FETCH_HEAD~1 FETCH_HEAD --copyrepo --breakingchanges || $IGNORE_BREAKING_CHANGES
   - go run ./tools/pkgchk/main.go ./services --exceptions ./tools/pkgchk/exceptions.txt
   - git diff --exit-code
+
+cache:
+  directories:
+    - $GOPATH/pkg/dep

swagger_to_sdk_config.json

@@ -1,6 +1,7 @@
 {
   "meta": {
     "after_scripts": [
+      "dep ensure",
       "go generate ./profiles/generate.go",
       "gofmt -w ./profiles/",
       "gofmt -w ./services/"