Merge pull request #1069 from infosiftr/mongo-3.1.8

Update mongo to 3.1.8

library/mongo

@@ -15,5 +15,5 @@
 3: git://github.com/docker-library/mongo@d5aca073ca71a7023e0d4193bd14642c6950d454 3.0
 latest: git://github.com/docker-library/mongo@d5aca073ca71a7023e0d4193bd14642c6950d454 3.0
 
-3.1.7: git://github.com/docker-library/mongo@3e6585721fc78b156a5ce832cf9bb282bbf833ab 3.1
-3.1: git://github.com/docker-library/mongo@3e6585721fc78b156a5ce832cf9bb282bbf833ab 3.1
+3.1.8: git://github.com/docker-library/mongo@14bbc085ef419c141b10595b04fe48c924a8c45e 3.1
+3.1: git://github.com/docker-library/mongo@14bbc085ef419c141b10595b04fe48c924a8c45e 3.1