Shift timestamps by 1 tuple for "steps" mode
Merge pull request #99 from andig/fix-timestamp-2

Shift timestamps by 1 tuple for "steps" mode
Make secondary axis configurable and add gas meter and valve
Merge pull request #102 from andig/axis

Make secondary axis configurable and add gas meter and valve
Merge pull request #103 from andig/master

Add Travis CI continuous integration