Release 0.3.0

See merge request !61

# Conflicts:
#   README.md
#   requirements.txt

F better errors

See merge request !59

Fix conan create on Windows

See merge request !58

- _CRT_SECURE_NO_WARNINGS suppresses warnings for "unsafe" fopen, strcpy etc.
- int -> size_t

On Windows, the static library for the protobuf component has to be explicitly linked in the test_package. This addresse issue #103

Specifying 'all' is not necessary and does not work on Windows. On Windows the target is called BUILD_ALL.

Fix deprecations + updates

See merge request !57

See !92 for the relevant issue.

Resolve "Unit tests unter Windows"

See merge request !56

- Fix GTest spelling in test/CMakeLists.txt
- Restrict vcpkg triplet to release
- Add set(CMAKE_POSITION_INDEPENDENT_CODE ON)
- Include of <gtest/gtest.h> in tests instead of smaller headers
- Add boost options to CMakeLists.txt

This should be done by the Docker image

For activating the conan venv in ~/.bashrc

- Add test targets for both Debug and Release