Format constants file better

Update constants_formatting to match google style guide, and output
clang-formatted output.

Change-Id: Ic04798c85193cab525e243be5a934d6217937517
diff --git a/y2019/vision/constants.h b/y2019/vision/constants.h
index b33b045..cc6775e 100644
--- a/y2019/vision/constants.h
+++ b/y2019/vision/constants.h
@@ -30,7 +30,7 @@
     return out;
   }
 
-  void dump(std::basic_ostream<char> &o) const;
+  void Dump(std::basic_ostream<char> *o) const;
 };
 
 struct IntrinsicParams {
@@ -53,7 +53,7 @@
     out.barrel_mount = data[2];
     return out;
   }
-  void dump(std::basic_ostream<char> &o) const;
+  void Dump(std::basic_ostream<char> *o) const;
 };
 
 // Metadata about the calibration results (Should be good enough to reproduce).
@@ -68,7 +68,7 @@
   const char *filename_prefix;
   int num_images;
 
-  void dump(std::basic_ostream<char> &o) const;
+  void Dump(std::basic_ostream<char> *o) const;
 };
 
 struct CameraCalibration {