No more need for travis button in README
No more need for travis button in README

pfmoore/invoke,mkusz/invoke,frol/invoke,pfmoore/invoke,singingwolfboy/invoke,sophacles/invoke,mattrobenolt/invoke,frol/invoke,mattrobenolt/invoke,pyinvoke/invoke,kejbaly2/invoke,tyewang/invoke,pyinvoke/invoke,kejbaly2/invoke,mkusz/invoke