Integrate the BAMI simulation framework in Gumby

[devos50]

Currently, we have some simulation code included in the BAMI repository. After discussions with @grimadas, it makes more sense to integrate this code in Gumby. Ideally, one should be able to set a flag that enables simulation of an experiment on a local computer. Moving this code to Gumby would also enable experiment designers to use scenario files in their simulations.