Fixes #71

1.15.0 python:3.6

• update kafka_python from 1.4.3 back to 1.4.4
• update requests from 2.20.0 back to 2.20.1
• update virtualenv from 16.0.0 back to 16.1.0
• update twisted from 18.7.0 back to 18.9.0
• update scikit-learn from 0.20.0 back to 0.20.1
• update cloudant from 2.9.0 back to 2.10.1
• update ibmcloudsql from 0.2.21 back to 0.2.23
• update psycopg2 from 2.7.5 back to 2.7.6.1
• update cassandra-driver from 3.15.1 back to 3.16.0

1.3.0 python:3.7

• update kafka_python from 1.4.3 back to 1.4.4
• update requests from 2.20.0 back to 2.20.1
• update virtualenv from 16.0.0 back to 16.1.0
• update twisted from 18.7.0 back to 18.9.0
• update scikit-learn from 0.20.0 back to 0.20.1
• update cloudant from 2.9.0 back to 2.10.1
• update ibmcloudsql from 0.2.21 back to 0.2.23
• update psycopg2 from 2.7.5 back to 2.7.6.1
• update redis from 2.10.6 back to 3.0.1
• update elasticsearch from 5.5.3 back to 6.3.1
• update cassandra-driver from 3.15.1 back to 3.16.0