BLD: update release number (#656)

BLD: new release num (#648)

BLD: new release (#640)

BLD: new release info (#612)

BLD: new-release (#590)

BLD: new release number (#572)

BLD: update version number (#489)

Merge branch 'master' of github.com:mie-lab/trackintel

increase version to 1.2.0

BLD: prepare for new release (#461)