Add copyrights and header guards.

Change-Id: I1e4c22a1626095750b6ffa8e0edd5e078ef221ec

test/unit/StringValueTest.h

@@ -1,3 +1,13 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2015. All Rights Reserved.                             */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#ifndef NT_TEST_STRINGVALUETEST_H_
+#define NT_TEST_STRINGVALUETEST_H_
+
 #include "Value.h"
 
 #include "gtest/gtest.h"
@@ -10,3 +20,5 @@ class StringValueTest : public ::testing::Test {
 };
 
 }  // namespace ntimpl
+
+#endif