Update Soy dependency to the latest version. (#500)

Updates Soy dependency to the latest version which supports proto imports and updates sample Soy template to use the new syntax.

Author: Jesse-Good

closure/repositories.bzl

@@ -745,10 +745,10 @@ def com_google_template_soy():
         name = "com_google_template_soy",
         licenses = ["notice"],  # Apache 2.0
         jar_urls = [
-            "https://mirror.bazel.build/repo1.maven.org/maven2/com/google/template/soy/2019-07-14/soy-2019-07-14.jar",
-            "https://repo1.maven.org/maven2/com/google/template/soy/2019-07-14/soy-2019-07-14.jar",
+            "https://mirror.bazel.build/repo1.maven.org/maven2/com/google/template/soy/2020-08-24/soy-2020-08-24.jar",
+            "https://repo1.maven.org/maven2/com/google/template/soy/2020-08-24/soy-2020-08-24.jar",
         ],
-        jar_sha256 = "981d9f6180b40eb340f53d20aa1af630139ea079f95a3441265e87d8c850a527",
+        jar_sha256 = "60c59b9f5d3074b5b72b18f00efd4c96d10deb0693a16f40ce538657c51f63a4",
         deps = [
             "@args4j",
             "@com_google_code_findbugs_jsr305",

closure/templates/test/greeter_proto.soy

@@ -14,12 +14,13 @@
 
 {namespace io.bazel.rules.closure.soy.protoGreeter}
 
+import {Person} from 'closure/templates/test/person.proto';
 
 /**
  * Greets a person.
  */
 {template .greet}
-  {@param person: io.bazel.rules.closure.soy.Person}
+  {@param person: Person}
 
   {call io.bazel.rules.closure.soy.greeter.greet}
     {param name kind="text"}