Drop extraneous calculator reference in metadata

Author: addyosmani

metadata.html

@@ -2,7 +2,6 @@
 <link rel="import" href="../paper-radio-group/metadata.html">
 <link rel="import" href="../paper-checkbox/metadata.html">
 <link rel="import" href="../paper-toggle-button/metadata.html">
-<link rel="import" href="../paper-calculator/metadata.html">
 <link rel="import" href="../paper-progress/metadata.html">
 <link rel="import" href="../paper-slider/metadata.html">
 <link rel="import" href="../paper-input/metadata.html">