Re-write integration tests for registering.

[okdistribute]

The integration tests for registering and logging into accounts has been broken undeterministically.

They used to look like this:

https://github.com/datproject/datproject.org/blob/e8b1a801bf8250566c26f999906df042a33b882f/tests/e2e/user.js#L16-L26

but would half of the time fail like this:

https://travis-ci.org/datproject/datproject.org/builds/238098255#L2178

@clkao said it is likely a bug in nightwatch.js

I removed the tests for now because we need to move forward with release, but we should try to fix this.

[clkao]

Should we just todo this test rather than completely removing it?