Make sure python-dateutil 2.0 is not installed

contrib/requirements/default.txt

@@ -1,4 +1,4 @@
-python-dateutil
-anyjson
-kombu>=1.0.7
-pyparsing>=1.5.0
+python-dateutil>=1.5.0,<2.0.0
+anyjson>=0.3.1
+kombu>=1.0.7,<2.0.0
+pyparsing>=1.5.0,<2.0.0

setup.cfg

@@ -40,7 +40,7 @@ upload-dir = docs/.build/html
 requires = uuid
            importlib
            multiprocessing == 2.6.2.1
-           python-dateutil
-           anyjson
+           python-dateutil <= 1.5.0
+           anyjson >= 0.3.1
            kombu >= 1.0.7
            pyparsing >= 1.5.0

setup.py

@@ -48,10 +48,10 @@ try:
 except ImportError:
     install_requires.append("importlib")
 install_requires.extend([
-    "python-dateutil",
-    "anyjson",
-    "kombu>=1.0.7",
-    "pyparsing>=1.5.0",
+    "python-dateutil>=1.5.0,<2.0.0",
+    "anyjson>=0.3.1",
+    "kombu>=1.0.7,<2.0.0",
+    "pyparsing>=1.5.0,<2.0.0",
 ])
 py_version = sys.version_info
 is_jython = sys.platform.startswith("java")