remove(dep): Remove dep on plumbum

- Plumbum is not on the openstack global requirements list, and removing
  it as a requirement is a prerequisite to being accepted as an
  Openstack project

requirements.txt

@@ -1,6 +1,5 @@
 Werkzeug==0.9.4
 requests==2.0.0
 cherrypy==3.2.4
-plumbum==1.4.0
 stevedore==0.13
 -e git+https://github.com/racker/teeth-rest.git@e876c0fddd5ce2f5223ab16936f711b0d57e19c4#egg=teeth_rest

teeth_agent/hardware.py

@@ -17,8 +17,8 @@ limitations under the License.
 import abc
 import collections
 import os
+import subprocess
 
-import plumbum
 import stevedore
 import structlog
 
@@ -121,14 +121,14 @@ class GenericHardwareManager(HardwareManager):
                 for name in iface_names
                 if self._is_device(name)]
 
-    def _cmd(self, command_name):
-        """Mocking plumbum is frustratingly difficult. Instead, mock this."""
-        return plumbum.local[command_name]
+    def _cmd(self, command):
+        process = subprocess.Popen(command, stdout=subprocess.PIPE)
+        return process.communicate()
 
     def _list_block_devices(self):
-        report = self._cmd('blockdev')('--report').strip()
+        report = self._cmd(['blockdev', '--report'])[0]
         lines = report.split('\n')
-        lines = [line.split() for line in lines]
+        lines = [line.split() for line in lines if line is not '']
         startsec_idx = lines[0].index('StartSec')
         device_idx = lines[0].index('Device')
         size_idx = lines[0].index('Size')

teeth_agent/tests/hardware.py

@@ -41,18 +41,16 @@ class TestGenericHardwareManager(unittest.TestCase):
 
     def test_get_os_install_device(self):
         self.hardware._cmd = mock.Mock()
-        self.hardware._cmd.return_value = blockdev = mock.Mock()
-        blockdev.return_value = (
+        self.hardware._cmd.return_value = (
             'RO    RA   SSZ   BSZ   StartSec            Size   Device\n'
             'rw   256   512  4096          0    249578283616   /dev/sda\n'
             'rw   256   512  4096       2048      8587837440   /dev/sda1\n'
             'rw   256   512  4096  124967424        15728640   /dev/sda2\n'
             'rw   256   512  4096          0     31016853504   /dev/sdb\n'
-            'rw   256   512  4096          0    249578283616   /dev/sdc\n')
+            'rw   256   512  4096          0    249578283616   /dev/sdc\n', '')
 
         self.assertEqual(self.hardware.get_os_install_device(), '/dev/sdb')
-        self.hardware._cmd.assert_called_once_with('blockdev')
-        blockdev.assert_called_once_with('--report')
+        self.hardware._cmd.assert_called_once_with(['blockdev', '--report'])
 
     def test_list_hardwre_info(self):
         self.hardware.list_network_interfaces = mock.Mock()