* rebase master and resolve conflicts
* pylint to makefile
* fix crash when pivot operator
* fix comments
* add precision argument
* query test
* wip
* fix ut
* rename
* set time_offsets to cache key
wip
* refactor get_df_payload
wip
* extra query cache
* cache ut
* normalize df
* fix timeoffset
* fix ut
* make cache key logging sense
* resolve conflicts
* backend follow up iteration 1
wip
* rolling window type
* rebase master
* py lint and minor follow ups
* pylintrc