Basic testing framework
Named test files properly
Rename files and functions with simpler names
Tests to validate arguments
Test the Kantrowitz method
More thoroughly test Kantrowitz
Merge branch 'feature/add-tests' into develop
Wrote test coverage for SSA method
Refactored SSA to work with column or range of years
Merge branch 'feature/refactor-ssa' into develop
Refactored Kantrowitz method to use dplyr instead of merge
Test coverage for a single name