Conan as the dependency management system

Use Conan to manage all rt-data's dependencies. 

Dependencies to add:
* [cppunit](https://github.com/GuillemCastro/conan-cppunit)
* [libcurl](https://github.com/bincrafters/conan-libcurl)
* [SQLiteCpp](https://github.com/bincrafters/conan-sqlitecpp)
* [JSON For Modern C++](https://github.com/vthiery/conan-jsonformoderncpp)
* g3log ???