Fix system tests, remove dependency on cloud core

Author: Jon Wayne Parrott

monitoring/nox.py

@@ -21,7 +21,6 @@
 
 LOCAL_DEPS = (
     os.path.join('..', 'api_core'),
-    os.path.join('..', 'core'),
 )
 
 
@@ -94,7 +93,7 @@ def system(session, py):
     session.install('.')
 
     # Run py.test against the system tests.
-    session.run('py.test', '--quiet', 'tests/system.py')
+    session.run('py.test', '--quiet', 'tests/system', *session.posargs)
 
 
 @nox.session

monitoring/setup.py

@@ -29,7 +29,6 @@
 # 'Development Status :: 5 - Production/Stable'
 release_status = 'Development Status :: 3 - Alpha'
 dependencies = [
-    'google-cloud-core<0.29dev,>=0.28.0',
     'google-api-core[grpc]<2.0.0dev,>=0.1.1',
 ]
 extras = {

monitoring/tests/unit/test__dataframe.py

@@ -53,11 +53,11 @@
 
 
 def parse_timestamps():
-    import datetime
-    from google.cloud._helpers import _RFC3339_MICROS
+    from google.api_core import datetime_helpers
 
-    return [datetime.datetime.strptime(t, _RFC3339_MICROS)
-            for t in TIMESTAMPS]
+    return [
+        datetime_helpers.from_rfc3339(t).replace(tzinfo=None)
+        for t in TIMESTAMPS]
 
 
 def generate_query_results():