Merge branch 'develop' into gh-pages
Merge branch 'master' into gh-pages
Disable not up to date pages and lists.
Fixing issue #2

I've removed Ukraine and resorted based upon country first.
Fixing issue #6

Replaced Lviv with Düsseldorf and I've added my name and contact
details.
Fixing issue #4 and #5

Disabled "hackathon" and disabled unused social media links in the
footer.
Replace hero.jpg image (issue #1)

Thanks to Frederik Schweiger for the permission to use:
https://www.flickr.com/photos/frederikschweiger/14510984897/in/photostream/
Resized to 1620 x 1080.
Add a "become a sponsor" page. (Issue #7)
Become a speaker: Using google forms.

The form also collect the abstract of the talk.
Add team members. (#15)

- Randy
- Resul
- Johan
- Jens
Removed committee section Issue #18
Fixing issue #18

Wrote about us text and restructured the page.
Also disabled blog comments since we don't need this.
Comment out "Rockstar Speakers" section (#20)

.. until we have the speaker list.
Fix layout of _includes/become-sponsor.html
"Stay up to date" and join the g+ community (#12).

Invite visitors to join the GDG Düsseldorf community (instead of an
email subscription). A link is provided.
become a speaker: Redirect to the google form.

Redirect to the google form instead of embedding it in an iframe.
Two posts: "Hello World" and "Call for papers"