Fix broken dependencies.

All our libraries that depended on `kubernetes` started breaking today.
The reason is that pip does not do a good job properly resolving the compatible package versions.
It just install packages in order without caring about the incompatibilities.
The urllib3 package installed is incompatible with the `requests` package that's getting installed later.

Changing the order fixes the issue.

requirements.txt

@@ -2,10 +2,10 @@ certifi>=14.05.14 # MPL
 six>=1.9.0  # MIT
 python-dateutil>=2.5.3  # BSD
 setuptools>=21.0.0  # PSF/ZPL
-urllib3>=1.23  # MIT
 pyyaml>=3.12  # MIT
 google-auth>=1.0.1  # Apache-2.0
 ipaddress>=1.0.17;python_version=="2.7"  # PSF
 websocket-client>=0.32.0,!=0.40.0,!=0.41.*,!=0.42.* # LGPLv2+
 requests # Apache-2.0
 requests-oauthlib # ISC
+urllib3>=1.23  # MIT