python3: Add mox3 dependency

Add mox3 dependency, mox is not python3 compliant so use
the mox3 port to help transition the testsuites to mock.

Change-Id: I2312b0bac69f8bc4d2d23b88a59a2e22f2073a9b
Signed-off-by: Chuck Short <chuck.short@canonical.com>

global-requirements.txt

@@ -101,6 +101,7 @@ httpretty>=0.6.3
 keyring>=1.6.1
 mock>=1.0
 mox>=0.5.3
+mox3>=0.7.0
 MySQL-python
 nose
 nose-exclude

tests/files/gr-base.txt

@@ -100,6 +100,7 @@ httpretty>=0.6.3
 keyring
 mock>=0.8.0
 mox>=0.5.3
+mox3>=0.7.0
 MySQL-python
 nose
 nose-exclude

tests/files/test-project.txt

@@ -4,6 +4,7 @@ discover
 feedparser
 fixtures>=0.3.12
 mox==0.5.3
+mox3==0.7.3
 MySQL-python
 psycopg2
 pylint==0.25.2