Fix 104

[sangeetabhatia03]

This PR fixes #104; I am now using readr to read in the mapping from parameter names to short parameter names.

Checklist:

• [X ] I have added new dependencies in DESCRIPTION
• [X ] I have bumped the version number in DESCRIPTION
• [ X] I have updated the NEWS.md
• [ NA] I have added unit tests using testthat
• [ NA] I have checked that the package can install locally using devtools::install_local("<path-to-epireview>")
• [ NA] I have added documentation where required
• [ NA] My documentation includes examples of how to use the function
• [ NA] If necessary, I have updated priority-pathogens