Bump Guava to 21.0

Change-Id: Id81705773d191db6a18153d8b2dd4abd2bfd0e60
diff --git a/lib/deps.json b/lib/deps.json
index d4efb01..2790907 100644
--- a/lib/deps.json
+++ b/lib/deps.json
@@ -112,8 +112,8 @@
     "ganymed-ssh2": "mvn:ch.ethz.ganymed:ganymed-ssh2:262",
     "gmetric4j": "mvn:info.ganglia.gmetric4j:gmetric4j:1.0.10",
     "gson": "mvn:com.google.code.gson:gson:jar:2.6.2",
-    "guava": "mvn:com.google.guava:guava:20.0",
-    "guava-testlib": "mvn:com.google.guava:guava-testlib:20.0",
+    "guava": "mvn:com.google.guava:guava:21.0",
+    "guava-testlib": "mvn:com.google.guava:guava-testlib:21.0",
     "hamcrest-all": "mvn:org.hamcrest:hamcrest-all:1.3",
     "hk2-api": "mvn:org.glassfish.hk2:hk2-api:2.5.0-b32",
     "hk2-locator": "mvn:org.glassfish.hk2:hk2-locator:2.5.0-b32",