updating to version 0.9.0

 THis commit changes the library version to 0.9.0 and the format
 version to 0.6.0. The new format version break compatibility
 which is caused by the new physics.

 There is also an update for the train_properties json
 format in this commit. This just explains the format changes in
 format 0.6.0.
3 jobs for main in 4 minutes and 32 seconds (queued for 2 seconds)