add boost/make_shared.hpp to pre include files
fix to use boost::make_shared in Agent tests

in
- Agent class tests
- ThreadAgent class tests
fix to use boost::make_shared in Environment & Sensor tests

in
- Environment class tests
- Sensor class tests
fix to use boost::make_shared in Thread tests
Merge pull request #21 from cad-san/fix-to-use-make_shared

Use boost::make_shared