Remove autoprefixer

[EWright212]

Removed auto-prefixer gem as it has been deprecated. Tested on latest versions of Chrome, Firefox and IE with no adverse impact noted.

[pablobm]

I had a surface look. I seems to me that most of the prefixes come from third-party libraries: normalize.css, selectize, and the datetime picker. These come with prefixed CSS already (I think).

The few instances where our own CSS is autoprefixed, it appears to be for very obscure and specialised properties and selectors. This is a list after some grepping:

  -webkit-appearance: none;
     -moz-appearance: none;
[type="color"]::-moz-placeholder, [type="date"]::-moz-placeholder, [type="datetime-local"]::-moz-placeholder, [type="email"]::-moz-placeholder, [type="month"]::-moz-placeholder, [type="number"]::-moz-placeholder, [type="password"]::-moz-placeholder, [type="search"]::-moz-placeholder, [type="tel"]::-moz-placeholder, [type="text"]::-moz-placeholder, [type="time"]::-moz-placeholder, [type="url"]::-moz-placeholder, [type="week"]::-moz-placeholder, input:not([type])::-moz-placeholder, textarea::-moz-placeholder {
[type="color"]:-ms-input-placeholder, [type="date"]:-ms-input-placeholder, [type="datetime-local"]:-ms-input-placeholder, [type="email"]:-ms-input-placeholder, [type="month"]:-ms-input-placeholder, [type="number"]:-ms-input-placeholder, [type="password"]:-ms-input-placeholder, [type="search"]:-ms-input-placeholder, [type="tel"]:-ms-input-placeholder, [type="text"]:-ms-input-placeholder, [type="time"]:-ms-input-placeholder, [type="url"]:-ms-input-placeholder, [type="week"]:-ms-input-placeholder, input:not([type]):-ms-input-placeholder, textarea:-ms-input-placeholder {
[type="color"]::-ms-input-placeholder, [type="date"]::-ms-input-placeholder, [type="datetime-local"]::-ms-input-placeholder, [type="email"]::-ms-input-placeholder, [type="month"]::-ms-input-placeholder, [type="number"]::-ms-input-placeholder, [type="password"]::-ms-input-placeholder, [type="search"]::-ms-input-placeholder, [type="tel"]::-ms-input-placeholder, [type="text"]::-ms-input-placeholder, [type="time"]::-ms-input-placeholder, [type="url"]::-ms-input-placeholder, [type="week"]::-ms-input-placeholder, input:not([type])::-ms-input-placeholder, textarea::-ms-input-placeholder {
  -webkit-font-kerning: normal;
  -webkit-text-decoration-skip: ink;
  -webkit-appearance: none;
     -moz-appearance: none;
  -webkit-font-smoothing: antialiased;
  -webkit-user-select: none;
     -moz-user-select: none;
      -ms-user-select: none;

I think we can do without them.

[pablobm]

Actually, can you also remove this file please? spec/example_app/browserslist I think it's configuration for autoprefixer.

[pablobm]

And another thing: could you please rebase/squash the commits into a single commit?

[nickcharlton]

I just did this as @EWright212 is starting her new job! Woo!

I'll merge it now.