Move over to ABSL logging and flags.

Removes gperftools too since that wants gflags.

Here come the fireworks.

Change-Id: I79cb7bcf60f1047fbfa28bfffc21a0fd692e4b1c
Signed-off-by: Austin Schuh <austin.linux@gmail.com>
diff --git a/y2020/constants.cc b/y2020/constants.cc
index b5456b4..7ae54b5 100644
--- a/y2020/constants.cc
+++ b/y2020/constants.cc
@@ -8,7 +8,8 @@
 #endif
 
 #include "absl/base/call_once.h"
-#include "glog/logging.h"
+#include "absl/log/check.h"
+#include "absl/log/log.h"
 
 #include "aos/network/team_number.h"
 #include "aos/stl_mutex/stl_mutex.h"