Merge branch 'patch-2' into 'master'

Update README.md

See merge request !242
4 jobs for master in 45 minutes and 51 seconds (queued for 13 seconds)
Name Stage Failure
failed
benchmarks_and_profiling Benchmarks And Profiling
    observations[h] = self.get(h)
File "/builds/flatland/flatland/examples/custom_observation_example_02_SingleAgentNavigationObs.py", line 38, in get
possible_transitions = self.env.rail.get_transitions(*agent.position, agent.direction)
TypeError: get_transitions() argument after * must be an iterable, not NoneType
ERROR: InvocationError for command /builds/flatland/flatland/.tox/profiling/bin/python benchmarks/profile_all_examples.py (exited with code 1)
___________________________________ summary ____________________________________
ERROR: benchmarks: commands failed
ERROR: profiling: commands failed
ERROR: Job failed: command terminated with exit code 1