use STL in place of Boost

[kejxu]

with ROS Melodic pushing C++ support to c++14, a series of STL libraries including std::bind, std::mutex, std::unique_lock can now be used to build a modern C++ code base

this change requires at least c++11; therefore, this repo needs to branch off for a melodic branch

this change likely needs to be updated after #52 gets merged

[clalancette]

this change requires at least c++11; therefore, this repo needs to branch off for a melodic branch

To be clear; because this is changing the public API of bond_core, this is going to need a noetic branch; we generally try not to break API/ABI in already released distros unless it is a critical fix.

[kejxu]

To be clear; because this is changing the public API of bond_core, this is going to need a noetic branch; we generally try not to break API/ABI in already released distros unless it is a critical fix.

thanks for pointing it out! that's a good point!