Drop ordereddict from requirements

ordereddict was present in requirements.txt to maintain compatibility
with Python 2.6. OpenStack dropped py2.6 support starting from Kilo.
Thus there is no need to maintain this requirement.

Change-Id: I7a1a7555a007a5f905fd0e8af1b3929476655695

murano/dsl/murano_method.py

@@ -12,6 +12,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import collections
 import inspect
 import types
 
@@ -20,11 +21,6 @@ import murano.dsl.typespec as typespec
 import murano.dsl.virtual_exceptions as virtual_exceptions
 import murano.dsl.yaql_expression as yaql_expression
 
-try:
-    from collections import OrderedDict  # noqa
-except ImportError:  # python2.6
-    from ordereddict import OrderedDict  # noqa
-
 
 macros.register()
 virtual_exceptions.register()
@@ -62,7 +58,7 @@ class MuranoMethod(object):
             if isinstance(arguments_scheme, types.DictionaryType):
                 arguments_scheme = [{key: value} for key, value in
                                     arguments_scheme.iteritems()]
-            self._arguments_scheme = OrderedDict()
+            self._arguments_scheme = collections.OrderedDict()
             for record in arguments_scheme:
                 if not isinstance(record, types.DictionaryType) \
                         or len(record) > 1:
@@ -102,7 +98,7 @@ class MuranoMethod(object):
         defaults = func_info.defaults or tuple()
         for i in xrange(len(defaults)):
             data[i + len(data) - len(defaults)][1]['Default'] = defaults[i]
-        result = OrderedDict([
+        result = collections.OrderedDict([
             (name, typespec.ArgumentSpec(
                 declaration, self._namespace_resolver))
             for name, declaration in data])

requirements.txt

@@ -12,7 +12,6 @@ Routes>=1.12.3,!=2.0
 WebOb>=1.2.3
 wsgiref>=0.1.2
 argparse
-ordereddict
 kombu>=2.5.0
 lockfile>=0.8
 pycrypto>=2.6