Add coveragerc file
Add missing unit tests
Fix lexer bug when lexing an empty string
Add starts_with, ends_with, and reverse function
Update min*/max* to support strings

Fixes #65.
Corrected expected results for perf tests.
Merge branch 'empty-lex-string' into develop

* empty-lex-string:
  Fix lexer bug when lexing an empty string
Merge branch 'more-functions-2' into develop

* more-functions-2:
  Add starts_with, ends_with, and reverse function
Merge branch 'trevorrowe-develop' into develop

* trevorrowe-develop:
  Corrected expected results for perf tests.
Update min/max docs with new signature
Merge branch 'min-max-str' into develop

* min-max-str:
  Update min/max docs with new signature
  Update min*/max* to support strings