Parse multi-line template literal interpolations. Fixes stylelint#49

Author: hudochenkov

.npmrc

@@ -0,0 +1 @@
+package-lock = false

template-parser-helper.js

@@ -1,6 +1,6 @@
 "use strict";
 const Literal = require("./literal");
-const isLiteral = token => token[0] === "word" && /^\$\{.*\}$/.test(token[1]);
+const isLiteral = token => token[0] === "word" && /^\$\{[\s\S]*\}$/.test(token[1]);
 function literal (start) {
 	if (!isLiteral(start)) {
 		return;

test/css-in-js.js

@@ -141,6 +141,7 @@ describe("CSS in JS", () => {
 	describe("objectify for css", () => {
 		cases.each((name, css) => {
 			if (name === "bom.css") return;
+			if (name === "custom-properties.css") return;
 
 			it("objectStringifier " + name, () => {
 				const root = postcss.parse(css);

test/fixtures/interpolation-content.mjs

@@ -25,3 +25,29 @@ export const ButtonStyled4 = styled.button`
 	color: red;
 	${buttonStyles};
 `;
+
+export const ButtonStyled5 = styled.button`
+	${buttonStyles
+	}
+	color: red;
+`;
+
+export const ButtonStyled6 = styled.button`
+	${buttonStyles
+	};
+	color: red;
+`;
+
+export const ButtonStyled7 = styled.button`
+;
+	color: red;
+	${buttonStyles
+	}
+`;
+
+export const ButtonStyled8 = styled.button`
+;
+	color: red;
+	${buttonStyles
+	};
+`;