Return secure HTTPS images, if possible

[pdehaan]

Fun! Turns out that in some cases we may get some Open Graph magic like og:image:secure_url which is an HTTPS URL (see http://ogp.me/#structured). It'd probably be nice to use this image if available instead of the HTTP og:image or og:image:url versions.

og:image:url - Identical to og:image.
og:image:secure_url - An alternate url to use if the webpage requires HTTPS.

— via http://ogp.me/#structured

Or a real-live example at https://www.mysecretwood.com/collections/our-rings?sort_by=best-selling:

<meta property="og:image" content="http://cdn.shopify.com/s/files/1/1197/3550/t/12/assets/logo.png?13093450641738266550">
<meta property="og:image:secure_url" content="https://cdn.shopify.com/s/files/1/1197/3550/t/12/assets/logo.png?13093450641738266550">

It looks like we're currently the same as Embedly proxy behavior, but seems like a simple fix to get more secure HTTPS images [when available].

node index --url "https://www.mysecretwood.com/collections/our-rings?sort_by=best-selling"

https://www.mysecretwood.com/collections/our-rings?sort_by=best-selling:
  images:
    embedly:
      -
        caption: null
        entropy: 1.93638247295
        height:  220
        size:    46404
        url:     http://cdn.shopify.com/s/files/1/1197/3550/t/12/assets/logo.png?13093450641738266550
        width:   303
    fathom:
      -
        entropy: 1
        height:  500
        url:     http://cdn.shopify.com/s/files/1/1197/3550/t/12/assets/logo.png?13093450641738266550
        width:   500
  url:
    embedly: https://www.mysecretwood.com/collections/our-rings
    fathom:  https://www.mysecretwood.com/collections/our-rings?sort_by=best-selling

[pdehaan]

Closing. Almost certain this belongs over in mozilla/page-metadata-parser#32 instead.