Update trace dependencies to fix the unit test (#3749)

* Fix trace unit test * Fix stuff

Author: liyanhui1228

trace/nox.py

@@ -14,6 +14,8 @@
 
 from __future__ import absolute_import
 
+import os
+
 import nox
 
 
@@ -41,7 +43,7 @@ def unit_tests(session, python_version):
  '--cov-config=.coveragerc',
  '--cov-report=',
  '--cov-fail-under=97',
- 'tests/',
+ os.path.join('tests', 'unit'),
  *session.posargs
  )
 

trace/setup.py

@@ -10,7 +10,7 @@
 install_requires = [
  'google-gax>=0.15.7, <0.16dev',
  'googleapis-common-protos[grpc]>=1.5.2, <2.0dev',
- 'google-cloud-core >= 0.24.0, < 0.25dev',
+ 'google-cloud-core >= 0.26.0, < 0.27dev',
 ]
 
 setup(

trace/tests/unit/test__gax.py

@@ -16,8 +16,6 @@
 
 import mock
 
-from google.cloud._testing import _GAXBaseAPI
-
 
 class _Base(object):
  project = 'PROJECT'