fix(deps): update dependency google-gax to ^0.26.0 (#153)

Author: renovate[bot]

packages/google-cloud-redis/package.json

@@ -43,7 +43,7 @@
     "predocs-test": "npm run docs"
   },
   "dependencies": {
-    "google-gax": "^0.25.0",
+    "google-gax": "^0.26.0",
     "lodash.merge": "^4.6.1",
     "protobufjs": "^6.8.8"
   },