Fix slate test command passing on Circle CI (#72)

src/tasks/includes/lint-reporter.js

@@ -1,6 +1,8 @@
 const gutil = require('gulp-util');
 const _ = require('lodash');
 
+const messages = require('./messages.js');
+
 /** Class representing a custom reporter for @shopify/theme-lint */
 export default class Reporter {
   constructor() {
@@ -53,6 +55,8 @@ export default class Reporter {
           return gutil.log(failure[0]);
         });
       });
+
+      throw new Error(messages.translationsFailed());
     }
 
     this.successes = this.failures = [];

src/tasks/includes/messages.js

@@ -73,6 +73,10 @@ const messages = {
       ' and run a full <slate deploy> as a result.';
   },
 
+  translationsFailed: () => {
+    return 'Translation errors detected.';
+  },
+
   invalidThemeId: (themeId, env) => {
     gutil.log('Invalid theme id for',
       gutil.colors.cyan(`${env}: ${themeId}`),