feat(a256gcm): Ban unsafeExplicitIV by default.

Use grunt-ban-words to ban unsafeExplicitIV
except where expected.

grunttasks/ban-word.js

@@ -0,0 +1,14 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+module.exports = function (grunt) {
+  grunt.config('word', {
+    unsafeExplicitIV: {
+      options: {
+        banList: ['unsafeExplicitIV']
+      },
+      src: ['app/scripts/**/*.js', '!app/scripts/lib/crypto/a256gcm.js', '!app/scripts/lib/crypto/recovery-keys.js']
+    }
+  });
+};

grunttasks/lint.js

@@ -8,6 +8,7 @@ module.exports = function (grunt) {
 
   var SUBTASKS = [
     'eslint',
+    'word',
     'jsonlint:app',
     'sasslint'
   ];

npm-shrinkwrap.json

@@ -6900,6 +6900,12 @@
         "babel-core": "^6.0.12"
       }
     },
+    "grunt-ban-word": {
+      "version": "0.1.1",
+      "resolved": "https://registry.npmjs.org/grunt-ban-word/-/grunt-ban-word-0.1.1.tgz",
+      "integrity": "sha1-5E7cSwzBX9hp4b0VrEsSMuLtQlA=",
+      "dev": true
+    },
     "grunt-bump": {
       "version": "0.7.0",
       "resolved": "https://registry.npmjs.org/grunt-bump/-/grunt-bump-0.7.0.tgz",

package.json

@@ -132,6 +132,7 @@
     "eslint-plugin-sorting": "git://github.com/shane-tomlinson/eslint-plugin-sorting.git#bcacb99d",
     "firefox-profile": "1.2.0",
     "fxa-conventional-changelog": "1.1.0",
+    "grunt-ban-word": "0.1.1",
     "grunt-bump": "0.7.0",
     "grunt-conventional-changelog": "6.1.0",
     "grunt-copyright": "0.3.0",