fix(deps): update dependency @google-cloud/promisify to v1 (#589)

renovate[bot] · JustinBeckwith · commit dad7530a1a4f · 2019-05-03T07:28:36.000-07:00
diff --git a/package.json b/package.json
@@ -54,7 +54,7 @@
     "@google-cloud/paginator": "^0.2.0",
     "@google-cloud/precise-date": "^0.1.0",
     "@google-cloud/projectify": "^0.3.0",
-    "@google-cloud/promisify": "^0.4.0",
+    "@google-cloud/promisify": "^1.0.0",
     "@sindresorhus/is": "^0.15.0",
     "@types/duplexify": "^3.6.0",
     "@types/long": "^4.0.0",
