Updated pytables version to 3.5.1 to address incomptability with latest versions

of pandas/numpy

Reference: pandas-dev/pandas#24839

Author: slack0

tox.ini

@@ -24,7 +24,7 @@ deps=
     pyOpenSSL
     pytest-logging
     pytest-localserver
-    tables==3.4.2
+    tables==3.5.1
     ./iotile_analytics_core
     ./iotile_analytics_interactive
     ./iotile_analytics_offline