Exclude yarn.lock from the whl file

Currently the airflow wheel is built with the yarn.lock which
is not actually used by the airflow itself. Having this file in the
docker image causes the clair and trivy scanners to fail.

The yarn.lock however is needed in sdist package that's why it should
not be excluded via MANIFEST.in

Alse asset compilation only happens when Airflow is installed
from sources. When Airflow is installed from packages, the
assets are already compiled-in during package building.

Dockerfile

@@ -253,13 +253,16 @@ RUN if [[ ${INSTALL_FROM_DOCKER_CONTEXT_FILES} == "true" ]]; then \
         bash /scripts/docker/install_from_docker_context_files.sh; \
     elif [[ ${INSTALL_FROM_PYPI} == "true" ]]; then \
         bash /scripts/docker/install_airflow.sh; \
+    else \
+        # only compile assets if the prod image is build from sources
+        # otherwise they are already compiled-in
+        bash /scripts/docker/compile_www_assets.sh; \
     fi; \
     if [[ -n "${ADDITIONAL_PYTHON_DEPS}" ]]; then \
         bash /scripts/docker/install_additional_dependencies.sh; \
     fi; \
     find /root/.local/ -name '*.pyc' -print0 | xargs -0 rm -r || true ; \
     find /root/.local/ -type d -name '__pycache__' -print0 | xargs -0 rm -r || true ; \
-    bash /scripts/docker/compile_www_assets.sh; \
     # make sure that all directories and files in .local are also group accessible
     find /root/.local -executable -print0 | xargs --null chmod g+x; \
     find /root/.local -print0 | xargs --null chmod g+rw

setup.cfg

@@ -161,6 +161,9 @@ install_requires =
     unicodecsv>=0.14.1
     werkzeug~=1.0, >=1.0.1
 
+[options.exclude_package_data]
+airflow.www = yarn.lock
+
 [options.packages.find]
 include =
     airflow*