sensors/zones: place in namespace and cleanup

Signed-off-by: Patrick Venture <venture@google.com>
Change-Id: I527dbc8477a232945f696227a7b0b2adbee45175
diff --git a/test/sensor_pluggable_unittest.cpp b/test/sensor_pluggable_unittest.cpp
index a15f06c..ffd08cd 100644
--- a/test/sensor_pluggable_unittest.cpp
+++ b/test/sensor_pluggable_unittest.cpp
@@ -7,6 +7,11 @@
 #include <gmock/gmock.h>
 #include <gtest/gtest.h>
 
+namespace pid_control
+{
+namespace
+{
+
 using ::testing::Invoke;
 
 TEST(PluggableSensorTest, BoringConstructorTest)
@@ -80,3 +85,6 @@
     EXPECT_CALL(*wip, write(value));
     p.write(value);
 }
+
+} // namespace
+} // namespace pid_control