keyframe percentages are a syntax error

[danc86]

In CSS animations, keyframes can be identified by a percentage. from is just a shortcut for 0% and to for 100%.

For example, from Mozilla Standup:

.animation-rainbow() {
0% { background-color: #cc3333; border-color: #cc3333; }
10% { background-color: #cc8f33; border-color: #cc8f33; }
20% { background-color: #adcc33; border-color: #adcc33; }
30% { background-color: #52cc33; border-color: #52cc33; }
40% { background-color: #33cc70; border-color: #33cc70; }
50% { background-color: #33cccc; border-color: #33cccc; }
60% { background-color: #3370cc; border-color: #3370cc; }
70% { background-color: #5233cc; border-color: #5233cc; }
80% { background-color: #ad33cc; border-color: #ad33cc; }
90% { background-color: #cc338f; border-color: #cc338f; }
100% { background-color: #cc3333; border-color: #cc3333; }
}

Currently lesscpy considers this a syntax error:

E: standup/static/less/magic.less line: 2, Syntax Error, token: `css_number`, `0%`