Use English when running Mocha tests

Gruntfile.js

@@ -90,6 +90,7 @@ module.exports = function(grunt) {
         src: 'test/*.js',
         options: {
           reporter: 'dot',
+          require: require.resolve('./test/helpers/use-english.js'),
         },
       },
       'unit-xml': {

test/helpers/use-english.js

@@ -0,0 +1,10 @@
+'use strict';
+
+var env = process.env;
+
+// delete any user-provided language settings
+delete env.LC_ALL;
+delete env.LC_MESSAGES;
+delete env.LANG;
+delete env.LANGUAGE;
+delete env.STRONGLOOP_GLOBALIZE_APP_LANGUAGE;

test/mocha.opts

@@ -0,0 +1 @@
+--require ./test/helpers/use-english