Support flex-basis: fill-available(stretch)

[yisibl]

TODO

Input

.foo {
   flex-basis: fill-available;
   width: fill-available;
}

Expected

.example {
   flex-basis: -moz-available;
   flex-basis: fill-available;
   width: -webkit-fill-available;
   width: -moz-available;
   width: fill-available;
}

[ai]

Mention me in the comment when you will finish the issue.