fix(client): use pyOpenSSL for improved security features

Author: mboersma

dev_requirements.txt

@@ -1,8 +1,14 @@
 # Deis client requirements
 docopt==0.6.2
+ndg-httpsclient==0.3.3
+pyasn1==0.1.7
+pyOpenSSL==0.15.1
 python-dateutil==2.4.2
+PyYAML==3.11
 requests==2.5.1
+tabulate==0.7.4
 termcolor==1.1.0
+urllib3==1.10.2
 
 # PyInstaller builds client binaries
 git+https://github.com/pyinstaller/pyinstaller@7413317