Test out piggyback

[knoiva-indecon]

Test out use of "piggyback" tools to add data to FrEDI from separate repo

• https://github.com/arunmallya/piggyback
• https://github.com/USEPA/FrEDI_Data

[knoiva-indecon]

Addressed by merge with initial_workflows branch:

• Moved data processing steps to FrEDI_Data repo (https://github.com/USEPA/FrEDI_Data)
• Added workflows to FrEDI_Data and (FrEDI to compile FrEDI data/import it into FrEDI