Fix two typos

Author: ctavan

lib/getenv.js

@@ -3,7 +3,7 @@ function _value(varName, fallback) {
   if (value === undefined) {
     if (fallback === undefined) {
       throw new Error('GetEnv.Nonexistent: ' + varName + ' does not exist ' +
-                      'and now fallback value provided.');
+                      'and no fallback value provided.');
     }
     return '' + fallback;
   }

test/getenv.js

@@ -2,7 +2,7 @@ var assert = require('assert');
 
 var getenv = require('../lib/getenv');
 
-//Setting getenv vars for testing
+// Setting env vars for testing
 process.env.TEST_GETENV_EMPTY_STRING = '';
 process.env.TEST_GETENV_STRING = 'This is a string.';
 process.env.TEST_GETENV_INT1 = '10';