Adding deps to protobuf rules.

Change-Id: Ib1f4f1e061a55885389a7b51c98317ee241a1bba
diff --git a/build_tests/proto_base.proto b/build_tests/proto_base.proto
new file mode 100644
index 0000000..8fc2143
--- /dev/null
+++ b/build_tests/proto_base.proto
@@ -0,0 +1,8 @@
+syntax = "proto2";
+
+package frc971;
+
+message BaseProto {
+  optional string a = 1;
+  optional string b = 2;
+}