Fix @observable decorator (fixes #191)
Fix @observable decorator (fixes #191)

mweststrate/MOBservable,andykog/mobservable,mobxjs/mobx,mobxjs/mobx,mobxjs/mobx,andykog/mobx,andykog/mobservable,mobxjs/mobx,andykog/mobx,mweststrate/MOBservable,mweststrate/MOBservable