Split logger.h into log_reader and log_writer

Much simpler!

Change-Id: I6c4ee363b56b67dac40c456261bbed79d01b8eb6
diff --git a/frc971/control_loops/drivetrain/BUILD b/frc971/control_loops/drivetrain/BUILD
index ad39bcf..8c3274d 100644
--- a/frc971/control_loops/drivetrain/BUILD
+++ b/frc971/control_loops/drivetrain/BUILD
@@ -470,7 +470,7 @@
         ":drivetrain_output_fbs",
         ":drivetrain_test_lib",
         "//aos/controls:control_loop_test",
-        "//aos/events/logging:logger",
+        "//aos/events/logging:log_writer",
         "//aos/testing:googletest",
         "//frc971/queues:gyro_fbs",
         "//frc971/wpilib:imu_fbs",
diff --git a/frc971/control_loops/drivetrain/drivetrain_lib_test.cc b/frc971/control_loops/drivetrain/drivetrain_lib_test.cc
index bfa3d26..b378484 100644
--- a/frc971/control_loops/drivetrain/drivetrain_lib_test.cc
+++ b/frc971/control_loops/drivetrain/drivetrain_lib_test.cc
@@ -6,7 +6,7 @@
 #include "aos/controls/control_loop_test.h"
 #include "aos/controls/polytope.h"
 #include "aos/events/event_loop.h"
-#include "aos/events/logging/logger.h"
+#include "aos/events/logging/log_writer.h"
 #include "aos/time/time.h"
 #include "gflags/gflags.h"
 #include "gtest/gtest.h"