v2: Vectorization improvements

Notable changes:

• Improve AVX implementations.
• Improve base implementations to allow for autovectorization.
• Improve CMake project organisation.
• Add support for RAW files.
• Improve documentation.
• Move automated tests from Travis to Github Actions.
• Improve tests.
• Add single-threaded benchmarks.
• Move from C++14 to C++17.

Full Changelog: v1...v2

v1: First release

• Implement any-order epistasis search.
• Implement new distribution strategy.
• Implement basic operations using explicit vectorization by including Intel AVX Intrinsics.
• Implement automatic testing using Travis.
• Implement benchmarking mini-programs.
• Add documentation using RTD.