cloudinit.net: add initialize_network_device function and tests

This is not yet called, but will be called in a subsequent Ec2-related branch to manually initialize a network interface with the responses using dhcp discovery without any dhcp-script side-effects. The functionality has been tested on Ec2 ubuntu and CentOS vms to ensure that network interface initialization works in both OS-types.

Since there was poor unit test coverage for the cloudinit.net.__init__ module, this branch adds a bunch of coverage to the functions in cloudinit.net.__init. We can also now have unit tests local to the cloudinit modules. The benefits of having unittests under cloudinit module:
 - Proximity of unittest to cloudinit module makes it easier for ongoing devs to know where to augment unit tests. The tests.unittest directory is organizated such that it
 - Allows for 1 to 1 name mapping module -> tests/test_module.py
 - Improved test and module isolation, if we find unit tests have to import from a number of modules besides the module under test, it will better prompt resturcturing of the module.

This also branch touches:
 - tox.ini to run unit tests found in cloudinit as well as include all test-requirements for pylint since we now have unit tests living within cloudinit package
 - setup.py to exclude any test modules under cloudinit when packaging

1 files changed, 11 insertions, 3 deletions

diff --git a/tox.ini b/tox.ini
index 1140f9b2..ef768847 100644
--- a/tox.ini
+++ b/tox.ini
@@ -21,7 +21,11 @@ setenv =
     LC_ALL = en_US.utf-8
 
 [testenv:pylint]
-deps = pylint==1.7.1
+deps = 
+    # requirements
+    pylint==1.7.1
+    # test-requirements because unit tests are now present in cloudinit tree 
+    -r{toxinidir}/test-requirements.txt
 commands = {envpython} -m pylint {posargs:cloudinit}
 
 [testenv:py3]
@@ -29,7 +33,7 @@ basepython = python3
 deps = -r{toxinidir}/test-requirements.txt
 commands = {envpython} -m nose {posargs:--with-coverage \
            --cover-erase --cover-branches --cover-inclusive \
-           --cover-package=cloudinit tests/unittests}
+           --cover-package=cloudinit tests/unittests cloudinit}
 
 [testenv:py27]
 basepython = python2.7
@@ -98,7 +102,11 @@ deps = pyflakes
 
 [testenv:tip-pylint]
 commands = {envpython} -m pylint {posargs:cloudinit}
-deps = pylint
+deps =
+    # requirements
+    pylint
+    # test-requirements
+    -r{toxinidir}/test-requirements.txt
 
 [testenv:citest]
 basepython = python3