Merge pull request #11 from karolsojko/gh-pages

Added Karol & Kacper presentations links
Merge pull request #12 from karolsojko/gh-pages

Added link to second meetup's gallery
Merge pull request #13 from karolsojko/gh-pages

Added info about third meetup
Merge pull request #14 from karolsojko/gh-pages

Added 3rd meetup sponsor
Added Avalton as sponsor of third meetup