pypeds enhancements

[joshuarobbins15]

Added a handful of functions and classes relating to fetching Excel files from https://nces.ed.gov/ipeds/use-the-data/download-access-database and fetching CYYYYDEP completion data for distance education programs. Additional details:

• Added a xlsx_parser function for parsing Excel files from "https://nces.ed.gov/ipeds/use-the-data/download-access-database"
• Added get_dep function to fetch CYYYYDEP completions survey data for distance education programs.
• Added get_cip function to fetch Excel documents from https://nces.ed.gov/ipeds/use-the-data/download-access-database. Used in C_CIP class to construct master CIP dimensional table,
• Added C_DEP class to construct distance education survey dataframe
• Added C_CIP class to construct dimensional/lookup CIP dataframe

[Btibert3]

Sorry, I don't know how I missed this. Adding in. Thanks for contributing!

[joshuarobbins15]

No problem and thank you!