Correctly report spec and suite duration

Previously, suite duration was always reported as 0 and spec duration
was always reported as null. Suites always used a no-op timer, and
specs set their result.duration after the result had already been sent
to reporters.

Fixes #1676.

src/core/Env.js

@@ -952,6 +952,7 @@ getJasmineRequireObj().Env = function(j$) {
         id: getNextSuiteId(),
         description: description,
         parentSuite: currentDeclarationSuite,
+        timer: new j$.Timer(),
         expectationFactory: expectationFactory,
         asyncExpectationFactory: suiteAsyncExpectationFactory,
         expectationResultFactory: expectationResultFactory,