Add inspect method to Opcode.

lib/opcode.js

@@ -233,4 +233,13 @@ Opcode.isSmallIntOp = function(opcode) {
     ((opcode >= Opcode.map.OP_1) && (opcode <= Opcode.map.OP_16)));
 };
 
+/**
+ * Will return a string formatted for the console
+ *
+ * @returns {String} Script opcode
+ */
+Opcode.prototype.inspect = function() {
+  return '<Opcode: ' + this.toString() + ', hex: '+this.toHex()+', decimal: '+this.num+'>';
+};
+
 module.exports = Opcode;