Merge pull request #1813 from mattermost/PLT-1558

PLT-1558 adding session length to config file

docker/dev/config_docker.json

@@ -11,7 +11,11 @@
         "EnablePostIconOverride": false,
         "EnableTesting": false,
         "EnableDeveloper": false,
-        "EnableSecurityFixAlert": true
+        "EnableSecurityFixAlert": true,
+        "SessionLengthWebInDays" : 30,
+        "SessionLengthMobileInDays" : 30,
+        "SessionLengthSSOInDays" : 30,
+        "SessionCacheInMinutes" : 10
     },
     "TeamSettings": {
         "SiteName": "Mattermost",