Fixes (UglifyJs) lint warnings

Fix: Symbol exports is declared but not referenced [lib/b64.js:3,12]
   Fix: Symbol ZERO is declared but not referenced [lib/b64.js:10,5]
   Fix: Symbol res is declared but not referenced [test/convert.js:14,1]

lib/b64.js

@@ -7,7 +7,6 @@ var lookup = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
     ? Uint8Array
     : Array
 
-	var ZERO   = '0'.charCodeAt(0)
 	var PLUS   = '+'.charCodeAt(0)
 	var SLASH  = '/'.charCodeAt(0)
 	var NUMBER = '0'.charCodeAt(0)
@@ -116,6 +115,6 @@ var lookup = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
 		return output
 	}
 
-	module.exports.toByteArray = b64ToByteArray
-	module.exports.fromByteArray = uint8ToBase64
-}())
+	exports.toByteArray = b64ToByteArray
+	exports.fromByteArray = uint8ToBase64
+}(typeof exports === 'undefined' ? (this.base64js = {}) : exports))

test/convert.js

@@ -10,8 +10,7 @@ var test = require('tape'),
 		'sup',
 		'sup?',
 		'sup?!'
-	],
-	res;
+	];
 
 test('convert to base64 and back', function (t) {
   t.plan(checks.length);
@@ -49,4 +48,4 @@ function map (arr, callback) {
 		}
 	}
 	return res;
-}
+}