Limit upper version of requirements

Author: penguinolog

requirements.txt

@@ -1,9 +1,9 @@
 paramiko>=2.4  # LGPLv2.1+
 tenacity>=4.4.0  # Apache-2.0
 six>=1.10.0  # MIT
-threaded>=1.0  # Apache-2.0
+threaded>=1.0,<2.0  # Apache-2.0
 PyYAML>=3.12  # MIT
-advanced-descriptors>=1.0  # Apache-2.0
+advanced-descriptors>=1.0,<2.0  # Apache-2.0
 typing >= 3.6  # PSF
 futures>=3.1; python_version == "2.7"
 enum34>=1.1; python_version == "2.7"