babel-code-frame: Get rid of the line-numbers dependency.

packages/babel-code-frame/src/index.js

@@ -1,7 +1,5 @@
 /* eslint indent: 0 */
-/* eslint max-len: 0 */
 
-import lineNumbers from "line-numbers";
 import repeating from "repeating";
 import jsTokens from "js-tokens";
 import esutils from "esutils";
@@ -97,20 +95,19 @@ export default function (
     end = lines.length;
   }
 
-  let frame = lineNumbers(lines.slice(start, end), {
-    start: start + 1,
-    before: "  ",
-    after: " | ",
-    transform(params) {
-      if (params.number !== lineNumber) {
-        return;
-      }
+  let numberMaxWidth = String(end).length;
 
-      if (colNumber) {
-        params.line += `\n${params.before}${repeating(" ", params.width)}${params.after}${repeating(" ", colNumber - 1)}^`;
-      }
-
-      params.before = params.before.replace(/^./, ">");
+  let frame = lines.slice(start, end).map((line, index) => {
+    let number = start + 1 + index;
+    let paddedNumber = ` ${number}`.slice(-numberMaxWidth);
+    let gutter = ` ${paddedNumber} | `;
+    if (number === lineNumber) {
+      let markerLine = colNumber
+        ? `\n ${gutter.replace(/\d/g, " ")}${repeating(" ", colNumber - 1)}^`
+        : "";
+      return `>${gutter}${line}${markerLine}`;
+    } else {
+      return ` ${gutter}${line}`;
     }
   }).join("\n");