requires arguments to be strings
relaxes requirements for timed function arguments
Merge branch 'feature/require-string-args' into develop
prettify internal report() method
consolidate construction + collection of tf
fix/simplify calling function
check for identity, not equality
rename dummy to _dummy
Merge branch 'hotfix/arg-check-fix'
Merge tag 'arg-check-fix' into develop

fixes a bug having to do with the default arguments to timed functions.

Conflicts:
	simpletimeit/stimeit.py
Merge branch 'feature/refactorings' into develop