chore: add template README and tweak setup.py (#728)

- Add a license header to the empty `__init__.py` in the unit test directory. (OSPO's tool flags this as missing a license header.)
- Teak the setup.py so there are fewer manual adjustments needed during initial repo setup of a Cloud library.
- Add a generic README  with instructions on how to install the library locally. This is for the folks using the self-service approach. (A README for a published library needs more content like links to PyPI, links to documentation, etc.).

Author: busunkim96

gapic/templates/README.rst.j2

@@ -0,0 +1,50 @@
+Python Client for {{ api.naming.long_name }} API
+=================================================
+
+Quick Start
+-----------
+
+In order to use this library, you first need to go through the following steps:
+
+1. `Select or create a Cloud Platform project.`_
+2. `Enable billing for your project.`_
+3. Enable the {{ api.naming.long_name }} API.
+4. `Setup Authentication.`_
+
+.. _Select or create a Cloud Platform project.: https://console.cloud.google.com/project
+.. _Enable billing for your project.: https://cloud.google.com/billing/docs/how-to/modify-project#enable_billing_for_a_project
+.. _Setup Authentication.: https://googleapis.dev/python/google-api-core/latest/auth.html
+
+Installation
+~~~~~~~~~~~~
+
+Install this library in a `virtualenv`_ using pip. `virtualenv`_ is a tool to
+create isolated Python environments. The basic problem it addresses is one of
+dependencies and versions, and indirectly permissions.
+
+With `virtualenv`_, it's possible to install this library without needing system
+install permissions, and without clashing with the installed system
+dependencies.
+
+.. _`virtualenv`: https://virtualenv.pypa.io/en/latest/
+
+
+Mac/Linux
+^^^^^^^^^
+
+.. code-block:: console
+
+    python3 -m venv <your-env>
+    source <your-env>/bin/activate
+    <your-env>/bin/pip install /path/to/library
+
+
+Windows
+^^^^^^^
+
+.. code-block:: console
+
+    python3 -m venv <your-env>
+    <your-env>\Scripts\activate
+    <your-env>\Scripts\pip.exe install \path\to\library
+

gapic/templates/setup.py.j2

@@ -1,17 +1,27 @@
 {% extends '_base.py.j2' %}
 
 {% block content %}
+import io
+import os
 import setuptools  # type: ignore
 
+version = '0.1.0'
+
+package_root = os.path.abspath(os.path.dirname(__file__))
+
+readme_filename = os.path.join(package_root, 'README.rst')
+with io.open(readme_filename, encoding='utf-8') as readme_file:
+    readme = readme_file.read()
 
 setuptools.setup(
     name='{{ api.naming.warehouse_package_name }}',
-    version='0.0.1',
+    version=version,
+    long_description=readme,
     {% if api.naming.namespace -%}
     packages=setuptools.PEP420PackageFinder.find(),
     namespace_packages={{ api.naming.namespace_packages }},
     {% else -%}
-    packages=setuptools.find_packages(),
+    packages=setuptools.PEP420PackageFinder.find(),
     {% endif -%}
     platforms='Posix; MacOS X; Windows',
     include_package_data=True,
@@ -24,9 +34,6 @@ setuptools.setup(
     {%- endif %}
     ),
     python_requires='>=3.6',
-    scripts=[
-        'scripts/fixup_{{ api.naming.versioned_module_name }}_keywords.py',
-    ],
     classifiers=[
         'Development Status :: 3 - Alpha',
         'Intended Audience :: Developers',

gapic/templates/tests/unit/gapic/%name_%version/%sub/__init__.py.j2

@@ -1 +1,2 @@
 
+{% extends '_base.py.j2' %}