fix: correct Long types import (#358)

Author: SimenB

handwritten/datastore/package.json

@@ -49,6 +49,7 @@
     "@google-cloud/projectify": "^1.0.0",
     "@google-cloud/promisify": "^1.0.0",
     "@types/duplexify": "^3.6.0",
+    "@types/long": "^4.0.0",
     "arrify": "^2.0.0",
     "concat-stream": "^2.0.0",
     "extend": "^3.0.1",

handwritten/datastore/proto/datastore.d.ts

@@ -1,5 +1,5 @@
 import * as $protobuf from "protobufjs";
-import * as long from "long";
+import * as Long from "long";
 /** Namespace google. */
 export namespace google {