Fix false-negative with linebreaks inside the SVG tag (#29)

Author: StephanHoyer

index.js

@@ -6,7 +6,7 @@ const isSvg = input => {
 		return false;
 	}
 
-	input = input.toString().trim();
+	input = input.toString().trim().replace(/\n/g, ' ');
 
 	if (input.length === 0) {
 		return false;

test.js

@@ -20,6 +20,13 @@ test('valid SVGs', t => {
 <svg version="1.1">
 </svg>
 `));
+	t.true(isSvg(`<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<svg
+xmlns="http://www.w3.org/2000/svg"
+width="75"
+height="75"
+version="1.1"
+></svg>`));
 });
 
 test('invalid SVGs', t => {