Merge pull request #3661 from dnephin/fix_requirements

Add missing deps to requirements.txt

requirements.txt

@@ -1,9 +1,12 @@
 PyYAML==3.11
+backports.ssl-match-hostname==3.5.0.1; python_version < '3'
 cached-property==1.2.0
 docker-py==1.9.0rc2
 dockerpty==0.4.1
 docopt==0.6.1
-enum34==1.0.4
+enum34==1.0.4; python_version < '3.4'
+functools32==3.2.3.post2; python_version < '3.2'
+ipaddress==1.0.16
 jsonschema==2.5.1
 requests==2.7.0
 six==1.7.3