Add travis pylint CI

.travis.yml

@@ -0,0 +1,7 @@
+language: python
+python: ["3.5"]
+install: 
+    - "pip install -r requirements.txt"
+    - "pip install pylint"
+script:
+    - "pylint app_service.py -E"

app_service.py

@@ -8,7 +8,6 @@ import html
 import json
 import logging
 import mimetypes
-import sys
 from datetime import datetime
 from time import time
 from urllib.parse import unquote, quote, urlparse, parse_qs