Update some dependencies because of security warnings

requirements.txt

@@ -18,7 +18,7 @@ graypy==0.2.12
 Django==1.11
 django-extensions==1.7.8
 django-debug-toolbar==1.7
-gunicorn==19.1.1
+gunicorn==19.9.0
 akismet==0.2.0
 django-cors-headers==2.0.2
 django-oauth2-provider==0.2.6.1
@@ -28,7 +28,7 @@ djangorestframework-xml==1.3.0
 djangorestframework-yaml==1.0.3
 django-oauth-toolkit==0.10.0
 django-object-actions==0.8.2
-pillow==2.6.0
+pillow==5.2.0
 #apt-get install libjpeg-dev
 #apt-get install zlib1g-dev
 #apt-get install libpng12-dev