add sample credntial file for gbq

Author: rzitomer

credentials_file.json

@@ -0,0 +1,12 @@
+{
+  "type": "INSERT_TYPE",
+  "project_id": "INSERT_PROJECT_ID",
+  "private_key_id": "INSERT_PRIVATE_KEY_ID",
+  "private_key": "INSERT_PRIVATE_KEY",
+  "client_email": "INSERT_EMAIL",
+  "client_id": "INSERT_CLIENT_ID",
+  "auth_uri": "INSERT_AUTH_URI",
+  "token_uri": "INSERT_TOKEN_URI",
+  "auth_provider_x509_cert_url": "INSERT_AUTH_CERT_URL",
+  "client_x509_cert_url": "INSERT_CLIENT_CERT_URL"
+}