Boost not provide pkg-config file, so if execute
'pkg-config --exist cppkafka' command with boost dependency,
user always gets non-zero return. And PKG_SEARCH_MODULE in cmake
use the command to check the status of cppkafka.
The boost dependency should be removed for general usage can be works.
In the current implementation, library suffixes are hard coded from a hand-maintained list. Instead of writing this list, we can use the CMake macros for platform specific library prefix/suffixes.
E.g. https://cmake.org/cmake/help/v3.0/variable/CMAKE_STATIC_LIBRARY_SUFFIX.html
This also resolves library resolution on Mac OSX, which does not currently work on the native `.dylib` suffix for shared libraries.
