Add support for "isolate" value in "unicode-bidi"

[Krinkle]

The following should afaik not generate any warnings:

.mw-example {
    unicode-bidi: -moz-isolate;
    unicode-bidi: -webkit-isolate;
    unicode-bidi: isolate;
}

.. as it does right now:

• Expected (normal | embed | bidi-override | inherit) but found '-moz-isolate'.
• Expected (normal | embed | bidi-override | inherit) but found '-webkit-isolate'.
• Expected (normal | embed | bidi-override | inherit) but found 'isolate'.

Properties should be known (listed in CSS3 specification) or be a vendor-prefixed property. (known-properties)

See also:

• CSS/unicode-bidi on MDN

[nschonni]

Missing properties should be reported (and PR'd 😄 ) to https://github.com/nzakas/parser-lib as per the contributing guide 😉

[jdforrester]

This was fixed in parser-lib v0.2.4, which is pulled in as of #448; would it be possible make a release to fix this issue?

[cvrebert]

@jdforrester See #514.

[Krinkle]

Switched to https://stylelint.io