Bump hub image dependencies

I bumped various dependencies and unpinned the patch version on many to
get better in sync with security patches etc.

images/hub/requirements.txt

@@ -5,7 +5,7 @@
 
 # https://github.com/jupyterhub/dummyauthenticator
 # https://pypi.org/project/jupyterhub-dummyauthenticator
-jupyterhub-dummyauthenticator==0.3.1
+jupyterhub-dummyauthenticator==0.3
 
 # https://github.com/jupyterhub/firstuseauthenticator
 # https://pypi.org/project/jupyterhub-firstuseauthenticator
@@ -34,35 +34,47 @@ mwoauth==0.3.7
 
 # https://github.com/globus/globus-sdk-python
 # https://pypi.org/project/globus_sdk
-globus_sdk[jwt]==1.5
+globus_sdk[jwt]==1.8
 
 # https://github.com/jupyterhub/nullauthenticator
 # https://pypi.org/project/nullauthenticator
 nullauthenticator==1.0
 
 # https://github.com/jupyterhub/oauthenticator
 # https://pypi.org/project/oauthenticator
-oauthenticator==0.10.0
+oauthenticator==0.10
 
 ## Spawners
 # ---------------------------------------------------------
 
 # https://github.com/jupyterhub/kubespawner
 # https://pypi.org/project/jupyterhub-kubespawner
-jupyterhub-kubespawner==0.11.1
+jupyterhub-kubespawner==0.11
 
 # https://github.com/kubernetes-client/python
 # https://pypi.org/project/kubernetes
-kubernetes==10.0.1
+kubernetes==10.0
 
 ## Other dependencies
 # ---------------------------------------------------------
 
-pymysql==0.9.2
-psycopg2==2.7.5
+# https://github.com/PyMySQL/PyMySQL
+# https://pypi.org/project/PyMySQL/
+pymysql==0.9
+
+# https://github.com/psycopg/psycopg2
+# https://pypi.org/search/?q=psycopg2
+psycopg2==2.8
+
+# https://pypi.org/project/pycurl/
 pycurl==7.43.0.*
-statsd==3.2.2
-cryptography==2.8.*
+
+# https://github.com/jsocol/pystatsd
+# https://pypi.org/project/statsd/
+statsd==3.3
+
+# https://pypi.org/project/cryptography/
+cryptography==2.8
 
 ## Useful tools
 # ---------------------------------------------------------