Revert "Create forecastmulti_track"

This reverts commit 3df0b8661dc05df5408fbced9dd29b60f88eef84.
Revert "Revert "Create forecastmulti_track""

This reverts commit 0572d4da54a09a871515dc9aea3d0cc38dd28b04.
Merge branch 'master' of https://github.com/nkosimuse/Forecast-Code