Remove plist_parser.py and omit external libraries from code coverage

.coveragerc

@@ -1,3 +1,4 @@
 [report]
 omit =
     */tests/*
+    */external/*

elodie/plist_parser.py

@@ -1,44 +0,0 @@
-"""
-Parse OS X plists.
-
-.. moduleauthor:: Jaisen Mathai <jaisen@jmathai.com>
-"""
-
-# load modules
-from os import path
-
-import plistlib
-
-
-class Plist(object):
-
-    """Parse and interact with a plist file.
-
-    This class wraps the `plistlib module`_ from the standard library.
-
-    .. _plistlib module: https://docs.python.org/3/library/plistlib.html
-
-    :param str source: Source to read the plist from.
-    """
-
-    def __init__(self, source):
-        if not path.isfile(source):
-            raise IOError('Could not load plist file %s' % source)
-        self.source = source
-        self.plist = plistlib.readPlist(self.source)
-
-    def update_key(self, key, value):
-        """Update a value in the plist.
-
-        :param str key: Key to modify.
-        :param value: New value.
-        """
-        self.plist[key] = value
-
-    def write_file(self, destination):
-        """Save the plist.
-
-        :param destination: Write the plist here.
-        :type destination: str or file object
-        """
-        plistlib.writePlist(self.plist, destination)