Migrate to Anaconda

Idea would be to lean on a pre-existing package manager to deal with the web of dependencies, versioning, etc.

(from @jendrikseipp )

Install `planutils` as a thin wrapper to Anaconda:

```
pip install planutils
```

Install conda, create and activate new environment into which packages will be installed, add conda package repository with conda packages for planners:

```
planutils setup
```

Ask user whether to install lama conda package, then possibly run lama:
```
lama domain.pddl problem.pddl
```

Added benefits of having minimal impact on `.bashrc` edits and a sandboxed environment for the planning stuff.