Adding pytransitions (ros#18478)

* added pytransitions

Add pytransitions (https://pypi.org/project/transitions/) for easy finite state machine implementation in python

* updated packages for other ubuntu/debian versions

* added wildcard for current distributions

* Corrected indentation

* adjusted indentation

rosdep/python.yaml

@@ -3947,6 +3947,20 @@ python-transforms3d-pip:
  ubuntu:
  pip:
  packages: [transforms3d]
+python-transitions:
+ debian:
+ '*': [python-transitions]
+ stretch:
+ pip:
+ packages: [transitions]
+ ubuntu:
+ '*': [python-transitions]
+ trusty:
+ pip:
+ packages: [transitions]
+ xenial:
+ pip:
+ packages: [transitions]
 python-trep:
  debian:
  pip: