CT-1572 copy latest version of repo to docker image when building
CT-1572 copy latest version of repo to docker image when building

Apparently our base image has the context automatically copied, while subsequent
images we create from it do not, so we have to add an explicit COPY command to
ensure the code is up-to-date in the new image we build with Dockerfile

ministryofjustice/correspondence_tool_staff,ministryofjustice/correspondence_tool_staff,ministryofjustice/correspondence_tool_staff,ministryofjustice/correspondence_tool_staff,ministryofjustice/correspondence_tool_staff