button: fixes style inconsistencies between 'md-buttons' using 'a' and 'button' under the hood
button: fixes style inconsistencies between 'md-buttons' using 'a' and 'button' under the hood

jhr007/ember-material-design,sumn2u/ember-material-design,mike1o1/ember-material-design,mize85/ember-material-design,mize85/ember-material-design,sumn2u/ember-material-design,jhr007/ember-material-design,mike1o1/ember-material-design