min and max don't recognize decimals without leading integer

[connorskees]

Not sure if this is considered a bug, but wanted to clarify behavior here.

For the given input

a {
  color: min(.2, .4);
  color: min(0.2, 0.4);
}

dart-sass will output

a {
  color: 0.2;
  color: min(0.2, 0.4);
}

The cause for this seems to be that this switch/case doesn't account for a leading decimal when parsing numbers. If this is intentional, it would be good to add this case to the spec tests.