Implement profile widget in header

[mkrause]

Closes #221

[mkrause]

@ismay This is done, basically. But there's one test I can't get to work. See Travis.

  it('navigates to the login page when clicking the login button', () => {
    const push = jest.fn()
    const wrapper = shallow(<DumbHeader hasAuth={false} history={{ push }} />)
    wrapper.find(RaisedButton).simulate('click')
    expect(push).toBeCalledWith('/login')
  })

I'm trying to get test coverage for the onTouchTap event in the Header component. I've tried a few variants of the above, but none are able to simulate the event (despite the name, a click event should trigger onTouchTap). Any ideas?

[ghost]

@mkrause Ah ok. I'll take a look at this next wednesday, will let you know!