feat: add multiple authentication methods, token and oidc.

token is the current token comparison, and oidc generates oidc token using client-credentials flow. in addition - add ping verification using the same method

vendor/github.com/pquerna/cachecontrol/.travis.yml

@@ -0,0 +1,10 @@
+language: go
+
+install:
+  - go get -d -v ./...
+  - go get -u github.com/stretchr/testify/require
+
+go:
+  - 1.7
+  - 1.8
+  - tip