Upgraded some dependencies

package.json

@@ -24,7 +24,7 @@
   "homepage": "https://github.com/syzoj/syzoj#readme",
   "dependencies": {
     "amqplib": "^0.5.2",
-    "ansi-to-html": "^0.6.8",
+    "ansi-to-html": "^0.6.9",
     "async-lock": "^1.1.3",
     "body-parser": "^1.15.2",
     "cheerio": "^1.0.0-rc.1",
@@ -36,30 +36,30 @@
     "express": "^4.14.0",
     "express-session": "^1.14.1",
     "file-size": "^1.0.0",
-    "fs-extra": "^7.0.0",
+    "fs-extra": "^7.0.1",
-    "gravatar": "^1.5.2",
+    "gravatar": "^1.8.0",
     "javascript-time-ago": "^1.0.30",
     "js-yaml": "^3.9.0",
     "jsondiffpatch": "0.3.11",
-    "jsonwebtoken": "^8.3.0",
+    "jsonwebtoken": "^8.4.0",
     "katex": "^0.10.0",
     "mathjax-node": "^2.1.1",
     "moemark": "^0.3.10",
     "moment": "^2.15.0",
     "msgpack-lite": "^0.1.26",
     "multer": "^1.2.0",
-    "mysql2": "^1.6.2",
+    "mysql2": "^1.6.4",
     "node-7z": "^0.4.0",
-    "nodemailer": "^4.1.0",
+    "nodemailer": "^4.7.0",
     "object-assign-deep": "^0.4.0",
     "pygmentize-bundled-cached": "^1.1.0",
     "randomstring": "^1.1.5",
     "request": "^2.74.0",
     "request-promise": "^4.1.1",
     "sendmail": "^1.1.1",
-    "sequelize": "^4.41.0",
+    "sequelize": "^4.41.2",
     "session-file-store": "^1.0.0",
-    "socket.io": "^2.0.3",
+    "socket.io": "^2.2.0",
     "syzoj-divine": "^1.0.2",
     "tmp-promise": "^1.0.3",
     "waliyun": "^3.1.1",