tty: expose hasColor and getColorDepth directly

Author: thunder-coding

lib/tty.js

@@ -161,4 +161,4 @@ WriteStream.prototype.getWindowSize = function() {
   return [this.columns, this.rows];
 };
 
-module.exports = { isatty, ReadStream, WriteStream };
+module.exports = { isatty, getColorDepth, hasColors, ReadStream, WriteStream };