Bug fixes

• size of radios is inconsistent with other knobs (#118)
• type annotation for storiesOf method (#124)
• ondevice select knob undefined value causes key error (#111)
• reset groupId in selectStory handler (#137)
• fix for status bar covering stories on android+expo (#88)
• on device knobs - number knob will convert a coma to a dot (#136) 
• some minor ui fixes