Removing googleapis-common-protos from deps in non-core packages. (…

…#4098)

* Removing `googleapis-common-protos` from deps in non-`core` packages.

Also

- removing `grpcio` from non-`core` packages.
- manually specifying the `grpcio` dep in core (rather than getting
  it from `googleapis-common-protos[grpc]`)

* Making `grpc` an extra for `core`.

* Adding `googleapis-common-protos` back to `videointelligence`.

packages/google-cloud-vision/setup.py

@@ -25,9 +25,8 @@
     readme = readme_file.read()
 
 REQUIREMENTS = [
-    'google-cloud-core >= 0.27.0, < 0.28dev',
+    'google-cloud-core[grpc] >= 0.27.1, < 0.28dev',
     'google-gax >= 0.15.14, < 0.16dev',
-    'googleapis-common-protos[grpc] >= 1.5.3, < 2.0dev',
 ]
 EXTRAS_REQUIRE = {
     ':python_version<"3.4"': ['enum34'],