fix tests for IE11

[cherifGsoul]

Skip a test checks for function name property

[phillipskevin]

I would just feature detect once by putting something like this at the top of the module

var supportsFunctionNames = (function() {
  var fn = function() {};
  return !!fn.name;
}());

and then wrap the whole test in

if (supportsFunctionNames) {
  onlyDevTest("from method returns an observation with a helpful name", function() {
    // ...
  });
}