kiji-end-to-end-tests: SCHEMA-902. Update README of end-to-end tests with python-base instructions.

issue: https://jira.kiji.org/browse/SCHEMA-902
review: https://review.kiji.org/r/2094
commit: https://github.com/kijiproject/kiji-end-to-end-tests/commit/93a9997ae6a85066ed3fa667b9add0c76b09190b
cassandra-maven-plugin: CMP-13. Build randomly fails

issue: https://jira.kiji.org/browse/CMP-13
review: https://review.kiji.org/r/2105
commit: https://github.com/kijiproject/cassandra-maven-plugin/commit/225c65fecb2c09cb74f51966b12d37494f3fcb88