Changes in this release:
- Using GIT submodules for all dependencies
- Dropped VS2013 support
- Basic support for storing gsl::byte/std::byte
- Simplified output stream implementation
- Fixed swap: using ADL instead of specializing std::swap
- Made SensitiveSegmentAllocator "really" noexcept-movable
Internal:
- Increased test coverage
- Updated Travis CI image
- Dropped Coverity integration (too buggy)