Update readme header

[simison]

Adds logo and makes header all around sexier

[OmgImAlexis]

Seems to be a tad broken.

[simison]

@OmgImAlexis yeah sorry, work-in-progress. :-) It's hard to see how it renders on github without PR.

[OmgImAlexis]

Use this and hit preview to check.

[simison]

Done!

Gotta clean out that history.md from this, somehow sneaked it in by squashing.

I'll merge if you agree is good.

[coveralls]

Coverage decreased (-0.3%) to 80.366% when pulling 1478bab on update-readme-header into bf98c65 on master.

[lushc]

Not sure if you were planning on doing this already, but I'd replace update-readme-header with master before merging, just in case this branch ever gets pruned 😅

[simison]

Yep totally, I'll have to replace this with https://cdn.rawgit.com/agenda/agenda/agenda.svg right before merging. Thanks. :-)

[simison]

BTW what's going on with Travis?

Lots of random hiccups!

1) Job job concurrency should run jobs as first in first out (FIFO) with respect to priority:
     Error: Timeout of 8000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves.

[OmgImAlexis]

That's expected. Loads of the tests rely on each other for some reason which causes timeouts to happen 50% of the time.

I have a fix for that but we need to switch to avajs first to allow process isolation and I can't do that until the xo PR gets merged.