Merge pull request #40 from mistercrunch/chart

Charting, may not belong in Airflow on the long run...
Fixing bug in LocalExecutor
Fix backfill expunge_all
Merge pull request #41 from mistercrunch/fix_backfill

Fix backfill expunge_all
Per line bash logging
Chart improvements
A few basic chart improvements
Merge pull request #42 from mistercrunch/chart_imp

A few chart improvements
enabling pandas
More chart improvments
Merge pull request #44 from mistercrunch/chart_imp

More chart improvments
Fix chart date type is different depending on maching
Yet more improvement to charts
Charts
Making the chart load async
Celery fix
Chart improvements
More chart improvements
More Chart ipmrovements
Merge pull request #47 from mistercrunch/chart_async

Chart async