Merge branch 'master' of gitlab.aicrowd.com:flatland/flatland into 66-shortest-path-predictor-cleanup-tests

editor bug fix : interaction with mouse

See merge request flatland/flatland!64

Resolve "shortest-path-predictor"

Closes #66

See merge request flatland/flatland!63

Merge branch 'master' of gitlab.aicrowd.com:flatland/flatland into 66-shortest-path-predictor-cleanup-tests

updated test to handle new predictor

Added potential conflict to tree observation as an 8th feature. ATTENTION this means that the observation space dimension has increased! will still check that this is handled correctly everywhere but looks good.