Adding tox support for AppVeyor.

In the process, fixing some Windows PATH issues in
"gcloud._helpers" and associated tests.

appveyor.yml

@@ -19,32 +19,38 @@ environment:
     - PYTHON: "C:\\Python27"
       PYTHON_VERSION: "2.7.11"
       PYTHON_ARCH: "32"
+      TOX_ENV: "py27"
 
     - PYTHON: "C:\\Python27-x64"
       PYTHON_VERSION: "2.7.11"
       PYTHON_ARCH: "64"
+      TOX_ENV: "py27"
 
     # Python 3.4.4 is the latest Python 3.4 with a Windows installer
     # Python 3.4.4 is the overall latest
     # https://www.python.org/ftp/python/3.4.4/
     - PYTHON: "C:\\Python34"
       PYTHON_VERSION: "3.4.4"
       PYTHON_ARCH: "32"
+      TOX_ENV: "py34"
 
     - PYTHON: "C:\\Python34-x64"
       PYTHON_VERSION: "3.4.4"
       PYTHON_ARCH: "64"
+      TOX_ENV: "py34"
 
     # Python 3.5.1 is the latest Python 3.5 with a Windows installer
     # Python 3.5.1 is the overall latest
     # https://www.python.org/ftp/python/3.5.1/
     - PYTHON: "C:\\Python35"
       PYTHON_VERSION: "3.5.1"
       PYTHON_ARCH: "32"
+      TOX_ENV: "py35"
 
     - PYTHON: "C:\\Python35-x64"
       PYTHON_VERSION: "3.5.1"
       PYTHON_ARCH: "64"
+      TOX_ENV: "py35"
 
 install:
   - ECHO "Filesystem root:"
@@ -83,7 +89,7 @@ build_script:
 test_script:
   - "%CMD_IN_ENV% pip list"
   # Run the project tests
-  - "%CMD_IN_ENV% py.test"
+  - "%CMD_IN_ENV% tox -e %TOX_ENV%"
 
 after_test:
   # If tests are successful, create binary packages for the project.

appveyor/requirements.txt

@@ -4,6 +4,7 @@
 # target Python version and architecture
 wheel
 pytest
+tox
 cryptography
 grpcio >= 1.0rc1
 grpc-google-pubsub-v1

gcloud/_helpers.py

@@ -57,7 +57,9 @@
     (?P<nanos>\d{1,9})                       # nanoseconds, maybe truncated
     Z                                        # Zulu
 """, re.VERBOSE)
-DEFAULT_CONFIGURATION_PATH = '~/.config/gcloud/configurations/config_default'
+_USER_ROOT = os.path.expanduser('~')
+DEFAULT_CONFIGURATION_PATH = os.path.join(_USER_ROOT, '.config', 'gcloud',
+                                          'configurations', 'config_default')
 
 
 class _LocalStack(Local):

unit_tests/test__helpers.py

@@ -191,8 +191,10 @@ def setUp(self):
         if self.temp_APPDATA:  # pragma: NO COVER Windows
             os.environ['APPDATA'] = self.temp_config_path
 
-        self.config_path = os.path.join(os.getenv('APPDATA', '~/.config'),
-                                        'gcloud', 'configurations')
+        config_default = os.path.join(os.path.expanduser('~'), '.config')
+        config_dir = os.getenv('APPDATA', config_default)
+        self.config_path = os.path.join(config_dir, 'gcloud',
+                                        'configurations')
         conf_path = os.path.join(self.temp_config_path, self.config_path)
         os.makedirs(conf_path)
         self.temp_config_file = os.path.join(conf_path, self.config_file)