Merge pull request #4 from jakubzapletal/master

April meetup
Merge pull request #5 from jakubzapletal/master

Fixed filename of sponsor logo
Merge pull request #6 from jakubzapletal/master

Added link and added info about language of talk
Merge pull request #7 from jakubzapletal/master

Corrected name of talks
Merge pull request #8 from jakubzapletal/master

Changed name Sudak`s talk
Added june meetup.