Merge master, small refactor

app/utils/emoji.js

@@ -0,0 +1,24 @@
+// @flow
+
+export function toCodePoint(unicodeSurrogates, sep) {
+  var r = [],
+    c = 0,
+    p = 0,
+    i = 0;
+  while (i < unicodeSurrogates.length) {
+    c = unicodeSurrogates.charCodeAt(i++);
+    if (p) {
+      r.push((0x10000 + ((p - 0xd800) << 10) + (c - 0xdc00)).toString(16));
+      p = 0;
+    } else if (0xd800 <= c && c <= 0xdbff) {
+      p = c;
+    } else {
+      r.push(c.toString(16));
+    }
+  }
+  return r.join(sep || '-');
+}
+
+export function emojiToUrl(string: text) {
+  return `https://twemoji.maxcdn.com/2/72x72/${toCodePoint(string)}.png`;
+}