Add more and improve testing

[fluvf]

This does a couple of things:

• Update test related packages to latest versions
• use opn-cli to open test.html
• changes to test.html (see fb8cd05 and 722ef3d)
• Make existing tests more explicit and comprehensive
• remove end() calls as requested
• add 3 new tests (see 67048ef, 731210b and 52503f5)

Some things still need work, mainly the proxy part, but I'll leave that to another pr, this is big enough as is. I left comments about these in the code.

Stuff to consider

• Installing tape-catch
  Currently not that useful, but will be if testing for garbage input becomes a thing (Check for invalid input #43)
• Code coverage tools
  I don't know how essential these would be in the long run in a small project like Crel, but at least having a look locally should give important insight on how comprehensive the tests currently are

[fluvf]

Let me know how you feel about handling weird object keys in the attributes. Implementing that would be kinda dirty atm.

[KoryNunn]

I don't want to lump work on you but at some stage I'd like to remove the t.end() calls, so if it makes your life easier, feel free :)

[fluvf]

Rebased! No more extra test grouping and removed those end() calls. I also left out the invalid attributes object tests, as I don't think crel should worry about them anyways. Also made some changes to npm test as some people don't use chrome :P

[KoryNunn]

Most of the tests fail, and not all of the tests finish.

[fluvf]

Most of the added tests concern handling invalid input, which crel doesn't do at all atm. The tests crash at the property manipulation, which is not implemented. I should probably move them over to #35, but for now you can just comment them out to see the rest of the tests.

[fluvf]

Rebased, removed property and invalid input tests, as those will be added in their own prs. (#35 and some other) All tests now run, and luckilly crel doesn't fail any of them

[fluvf]

@KoryNunn could you give this another look now that I've tidied it up

[KoryNunn]

Awesome work, thanks!