Merge pull request #2894 from mfigurnov/fix-truncation-warning

Fix truncation of value warning

diff --cc src/caffe/common.cpp
index 7077f37,b40760e..299d67d
--- 1/src/caffe/common.cpp
--- 2/src/caffe/common.cpp
+++ b/src/caffe/common.cpp
@@@ -1,5 -1,5 +1,6 @@@
 +#include <boost/thread.hpp>
  #include <glog/logging.h>
+ #include <cmath>
  #include <cstdio>
  #include <ctime>