version 10.0 is not compatible with typescript

[matt-blanchette]

Steps:

1. Upgrade from 9.2.1 to 10.0.0 or 10.0.1
2. Typescript compilation fails:

error TS2688: Cannot find type definition file for 'long'.
  The file is in the program because:
    Entry point for implicit type library 'long'

Expect upgrading to v10 shouldn't fail compile.

Cause:

Version 10.0 depends on google-gax 5.0.2-rc.1, which includes dependency @types/long ^5.0.0

This dependency is deprecated and was removed in google-gax latest version 5.0.1

Resolution:

Changing dependency google-gax version to non-rc 5.0.1 or later (latest 5.0.3) resolves the Typescript compile error.