Testing `undefined` on is.element.
Grouping and enhancing is.equal test cases.
Fixing is.equal for objects.
Optimizing is.equal to return early if value and other are strictly equal.
Removing this unnecessary Date.now shim.
Testing that the first argument to is.minimum and is.maximum is not NaN.
Testing for old-style arguments objects explicitly.
"undefined" is a reserved word in ES3 browsers.
is.arguments -> is.args, because reserved words.
Adding `npm run coverage`