Merge pull request #2527 from arangodb-helper/new_arangodb_version_3.1.8

Please upgrade to the ArangoDB Release 3.1.8

library/arangodb

@@ -12,6 +12,6 @@
 2.8.11: git://github.com/arangodb/arangodb-docker@05366cb4c6a6aab8e1ff9ca74c81b09d9a57b5b5 jessie/2.8.11
 
 
-3.1: git://github.com/arangodb/arangodb-docker@c2776c0587ceea1af3458b6c344f2229d59cc309 jessie/3.1.7
-3.1.7: git://github.com/arangodb/arangodb-docker@c2776c0587ceea1af3458b6c344f2229d59cc309 jessie/3.1.7
-latest: git://github.com/arangodb/arangodb-docker@c2776c0587ceea1af3458b6c344f2229d59cc309 jessie/3.1.7
+3.1: git://github.com/arangodb/arangodb-docker@4f5bb422c58f7d7e8f3477470fbabe8253c3fdae jessie/3.1.8
+3.1.8: git://github.com/arangodb/arangodb-docker@4f5bb422c58f7d7e8f3477470fbabe8253c3fdae jessie/3.1.8
+latest: git://github.com/arangodb/arangodb-docker@4f5bb422c58f7d7e8f3477470fbabe8253c3fdae jessie/3.1.8