sensors/zones: place in namespace and cleanup

Signed-off-by: Patrick Venture <venture@google.com>
Change-Id: I527dbc8477a232945f696227a7b0b2adbee45175
diff --git a/test/sensors_json_unittest.cpp b/test/sensors_json_unittest.cpp
index 4777ae3..7b3dbc3 100644
--- a/test/sensors_json_unittest.cpp
+++ b/test/sensors_json_unittest.cpp
@@ -4,6 +4,11 @@
 #include <gmock/gmock.h>
 #include <gtest/gtest.h>
 
+namespace pid_control
+{
+namespace
+{
+
 TEST(SensorsFromJson, emptyJsonNoSensors)
 {
     // If the json has no sensors, the map is empty.
@@ -127,3 +132,6 @@
     auto output = buildSensorsFromJson(j2);
     EXPECT_EQ(2, output.size());
 }
+
+} // namespace
+} // namespace pid_control