Remove dead-weight code #42

Candidate files for removal (path relative to root directory of the repository):

• Single GPU plasma/models/runner.py
  • HyperRunner class inside this script might repurposed for DeepHyper interface
• install-mpi.sh (used for Travis builds; do not delete yet. Or, replace with built-in package management on Travis).
• All references to Theano as backend to external Keras