sensors/zones: place in namespace and cleanup

Signed-off-by: Patrick Venture <venture@google.com>
Change-Id: I527dbc8477a232945f696227a7b0b2adbee45175
diff --git a/experiments/drive.cpp b/experiments/drive.cpp
index 22fd4b6..5fdbcf4 100644
--- a/experiments/drive.cpp
+++ b/experiments/drive.cpp
@@ -25,6 +25,9 @@
 #include <memory>
 #include <tuple>
 
+namespace pid_control
+{
+
 using tstamp = std::chrono::high_resolution_clock::time_point;
 
 #define DRIVE_TIME 1
@@ -259,3 +262,5 @@
 
     return 0;
 }
+
+} // namespace pid_control