Correct erroneous test

Because the Runnable under test is not part of a Suite, its context is
undefined. Prior to this commit, the error returned was a
runtime-generated `ReferenceError`, not a Mocha-generated `Error`.

Set the timeout via the `Runnable#timeout` method, and update the test
to assert the correct behavior (not implementation details such as the
message body of the generated error).
Add pending tests to test result data. Issue #1050

Resolves #1050

Adds test result for pending tests to results array. Pending tests will be
 are then reported individually as <testcase name="test1"></skipped></testcase>
Update history.md
Merge pull request #1051 from tkmunzwa/master

Add <testcase></skipped><testcase> for pending tests to xunit reporter

* tkmunzwa/master:
  Add pending tests to test result data. Issue #1050
Update history.md for #1051