Merge branch 'dev' into f-role

.gitlab-ci.yml

CMakeLists.txt

Makefile

README.md

RELEASE_GUIDELINES.md

conanfile.py

doc/CHANGELOG.md

doc/DEPENDENCIES.md

doc/FEATURES.md

include/caosdb/logging.h

requirements.txt

src/caosdb/connection.cpp

src/caosdb/file_transmission/download_request_handler.cpp

src/caosdb/file_transmission/upload_request_handler.cpp

src/caosdb/logging.cpp

src/caosdb/transaction.cpp

src/caosdb/unary_rpc_handler.cpp

test/test_transaction.cpp