added tests for optional max-age on statics

[MauriceButler]

Added tests as tape tests runnable from npm test.

As this is different to the other existing tests I have made this a different pull request.

Related to #7

[xavi-]

I'm not too familiar with the various test frameworks out there. Out of curiosity, why do you prefer tape?

[MauriceButler]

Personally I find tape simple to use.

Other than that there is no real reason other than it produces TAP output.

However there are any frameworks that produce TAP output. http://testanything.org/wiki/index.php/Main_Page

If the test suite outputs TAP then it can be used with many other tools such as Testling (https://ci.testling.com/)

[xavi-]

That makes sense. I do hear good things about TAP. Though, I'm not too keen on having two test suite laying around. I've done it with other projects and they never get merged. Over the weekend I'll take a look at tape and see how hard it'll be to covert all the existing tests.

[MauriceButler]

I agree on the 2 suites.

THats exactly why I made it 2 separate pull requests.

I actually was going to do it for you but ran out of time. :)