Update dependencies

Author: jackycute

package.json

@@ -13,7 +13,7 @@
   "dependencies": {
     "Idle.Js": "github:shawnmclean/Idle.js",
     "async": "^2.1.4",
-    "aws-sdk": "^2.7.15",
+    "aws-sdk": "^2.7.20",
     "blueimp-md5": "^2.6.0",
     "body-parser": "^1.15.2",
     "bootstrap": "^3.3.7",
@@ -38,7 +38,7 @@
     "formidable": "^1.0.17",
     "gist-embed": "~2.6.0",
     "handlebars": "^4.0.6",
-    "helmet": "^3.1.0",
+    "helmet": "^3.3.0",
     "highlight.js": "~9.9.0",
     "i18n": "^0.8.3",
     "imgur": "git+https://github.com/hackmdio/node-imgur.git",
@@ -54,7 +54,7 @@
     "keymaster": "^1.6.2",
     "list.js": "^1.3.0",
     "list.pagination.js": "^0.1.1",
-    "lodash": "^4.17.2",
+    "lodash": "^4.17.4",
     "lz-string": "1.4.4",
     "markdown-it": "^8.2.2",
     "markdown-it-abbr": "^1.0.4",
@@ -98,7 +98,7 @@
     "reveal.js": "^3.3.0",
     "scrypt": "^6.0.3",
     "select2": "^3.5.2-browserify",
-    "sequelize": "^3.27.0",
+    "sequelize": "^3.28.0",
     "sequelize-cli": "^2.5.1",
     "shortid": "2.2.6",
     "socket.io": "~1.7.2",
@@ -116,7 +116,7 @@
     "visibilityjs": "^1.2.4",
     "viz.js": "^1.4.1",
     "winston": "^2.3.0",
-    "xss": "^0.3.2"
+    "xss": "^0.3.3"
   },
   "engines": {
     "node": ">=4.x"
@@ -146,7 +146,7 @@
     "expose-loader": "^0.7.1",
     "extract-text-webpack-plugin": "^1.0.1",
     "file-loader": "^0.9.0",
-    "html-webpack-plugin": "^2.24.1",
+    "html-webpack-plugin": "^2.25.0",
     "imports-loader": "^0.7.0",
     "json-loader": "^0.5.4",
     "less": "^2.7.1",