Merge branch 'release/0.1.11' into develop
* Added method and tests to find tables within a query

* Added method and tests to find fields within a table
* Refactored the order by and group by to use field and table objects
* Removed print
* Converted aggregate fields lookup field to be a field object
* Fix potential bug if field is not a string
* Call correct field methods
* Added lag lead difference fields
* Updated partition by method
* updated to 0.2
Merge branch 'release/0.2'