Upgrade version to v1.1.0

Bump version to 1.0.0.

Set version to 0.8.1.

Add tests.

Add Visual Studio 2017 in AppVeyor CI.

Add installation rules in the CMake of the project (#22)

Update README.md. Fix example.

Add support for large maps/sets (more than 2^32 - 1 elements) through…

… an extra class template parameter (#18)

Reduce default max load factor to 0.75.

Bug correction, m_load_threshold should never be > max_size().