Fix prefixed animation name replacement

Author: kaisermann

.editorconfig

@@ -8,6 +8,9 @@ indent_size = 2
 charset = utf-8
 trim_trailing_whitespace = true
 
+[test/**/expected.css]
+insert_final_newline = false
+
 [{package.json,.travis.yml,.eslintrc.json}]
 indent_style = space
 indent_size = 2

src/css/Stylesheet.ts

@@ -4,11 +4,13 @@ import { getLocator } from 'locate-character';
 import Selector from './Selector';
 import getCodeFrame from '../utils/getCodeFrame';
 import hash from '../utils/hash';
-import isKeyframesNode from '../utils/isKeyframesNode';
+import removeCSSPrefix from '../utils/removeCSSPrefix';
 import Element from '../compile/nodes/Element';
 import { Validator } from '../validate/index';
 import { Node, Ast, Warning } from '../interfaces';
 
+const isKeyframesNode = (node: Node) => removeCSSPrefix(node.name) === 'keyframes'
+
 class Rule {
 	selectors: Selector[];
 	declarations: Declaration[];
@@ -97,7 +99,7 @@ class Declaration {
 	}
 
 	transform(code: MagicString, keyframes: Map<string, string>) {
-		const property = this.node.property && this.node.property.toLowerCase();
+		const property = this.node.property && removeCSSPrefix(this.node.property.toLowerCase());
 		if (property === 'animation' || property === 'animation-name') {
 			this.node.value.children.forEach((block: Node) => {
 				if (block.type === 'Identifier') {

src/utils/isKeyframesNode.ts

@@ -0,0 +1,3 @@
+export default function(name: string): string {
+	return name.replace(/^-((webkit)|(moz)|(o)|(ms))-/, '');
+}

src/utils/removeCSSPrefix.ts

@@ -23,10 +23,12 @@
 	}
 
 	.animated {
+		-webkit-animation: why 2s;
 		animation: why 2s;
 	}
 
 	.also-animated {
+		-webkit-animation: not-defined-here 2s;
 		animation: not-defined-here 2s;
 	}
 </style>