First working version

• added API section (5c89629)
• added missing arguments in the example that shows how to parse query strings without the dollar sign (fa48f7f)
• added known issue section (283138f)
• fixed missing installation step and added mutation test (74771cb)
• fixed indentation in travis configuration file (8a9cae7)
• added badges (e791d5a)
• using spaces instead of tabs in the documentation (427bbbc)
• added a first working version (a9c1cc4)