Updated tests to include basic sanity-check delete tests for admin routes
Added pdf upload/retrieval/deletion functionality
Cleaned up gitignore for heroku deployment
Added functionality for calculating date expired for a post
Modified put for PetVaccine to calculate expiration date
Reorganized function declaration to make it more readable
Restructured server directory to move pdf helpers to admin folder. Fixed code and confirmed upload/retrieve/delete pdf functionality.
Merge pull request #160 from gnauhnoj/feat/pdfHandling

PDF Handling, Deployment Changes, Date Calculation, Admin Delete Tests