[Gazebo] Create automatic environment generator

[Jbwasse2]

The data cleans_minimal.ipynb file in /dataAnalysis/develop/data_clean/ requires that the environment be created in a way that is described by https://github.com/alexandroid000/self-assembly/wiki/Gazebo:-Creating-New-Environments. This can also be used to easily streamline the process of testing out different environments.

A neccessary fix in the code would also be to change self-assembly/gazebo/src/weaselball_gazebo/plugins/stateRecorder.cpp so that waythe "verification" code doesn't depend on the environment.