Example/Showcase of Image Upload UX/UI?

Image uploading is a common feature in _many_ web/mobile applications.

> We are going to be using the Image Upload feature _extensively_ in [**`Time`**](https://github.com/dwyl/time)
to allow people to upload a photo showing evidence of their **_completed_ activity**.
(_if you cannot visualise the use-case of this, **please comment** in_: https://github.com/dwyl/time/issues/215)

Additionally there are _several_ classes of applications where image uploading is relevant:
+ Dedicated Photo Sharing App (_the obvious one_)
+ Messaging/Chat (_where "a picture is worth a thousand words"_) Look no further than [SnapChat!](https://en.wikipedia.org/wiki/Snapchat)
+ Personal/Company Finance & Accounting (_Uploading Receipts_)

By building a clearly-explained Image Upload example/tutorial with re-useable code,
we can help others get creative and spawn new Apps/Projects in the _community_.

# Todo

+ [ ] Create an start-to-finish Image Upload Example
+ [ ] Deploy it to Heroku
+ [ ] Make the code _generic_ and _modular_ so that _anyone_ can use it in their project.

Questions we need to ask/answer:
+ [ ] How do we _secure_ our `/upload` endpoint to avoid people using it maliciously to upload undesirable images.
+ [ ] Can we restrict the `Origin` of the upload?
+ [ ] Can the `Origin` be _spoofed_ by a command-line script?

> I'm not saying that we are _going_ to create an "image upload" **product**,
But the ability to upload files/images is a "standalone" feature that people _pay_ for!
e.g: https://apps.shopify.com/uploadery
> This is a feature that has _real_ value to end-users so if we build something _great_
> not only will the people using the @dwyl app find it _useful_,
> the wider _community_ will use it and _help_ us to _improve_ it!