Add constructor specs around Page
specs for Page#content
specs for Page#get
specs for Page#title
spec Page#htmlPath
spec Page#fileName
spec Page#date
Merge branch 'page-spec'

* page-spec:
  spec Page#date
  spec Page#fileName
  spec Page#htmlPath
  specs for Page#title
  specs for Page#get
  specs for Page#content
  Add constructor specs around Page