Upgrade to jclouds 2.1.2-SNAPSHOT

Notably this fixes listing inside a directory on Docker.  Fixes #279.

pom.xml

@@ -301,7 +301,7 @@
   <properties>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <java.version>1.7</java.version>
-    <jclouds.version>2.1.1</jclouds.version>
+    <jclouds.version>2.1.2-SNAPSHOT</jclouds.version>
     <slf4j.version>1.7.25</slf4j.version>
     <shade.prefix>${project.groupId}.shaded</shade.prefix>
     <surefire.version>2.20</surefire.version>