Bump deps of Truth, especially Guava dep to avoid problems like https…

…://stackoverflow.com/q/54635950/28465

RELNOTES=Updated many deps, especially to avoid conflicts with `com.google.guava:listenablefuture`.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=235577253

pom.xml

@@ -23,11 +23,11 @@
     <maven-enforcer-plugin.version>3.0.0-M2</maven-enforcer-plugin.version>
 
     <!-- Properties for multiple-artifact deps. -->
-    <auto-value.version>1.6.2</auto-value.version>
-    <checker-framework.version>2.5.3</checker-framework.version>
-    <guava.version>26.0</guava.version>
+    <auto-value.version>1.6.3</auto-value.version>
+    <checker-framework.version>2.5.5</checker-framework.version>
+    <guava.version>27.0.1</guava.version>
     <gwt.version>2.8.2</gwt.version>
-    <protobuf.version>3.6.0</protobuf.version>
+    <protobuf.version>3.6.1</protobuf.version>
     <!-- Property for protobuf-lite protocArtifact, which isn't a "normal" Maven dep. -->
     <protobuf-lite.protoc.version>3.1.0</protobuf-lite.protoc.version>
     <!-- Property for protobuf-java protocArtifact, which ought to be the same as protobuf.version but can't be internally at the moment. -->