build: docker tweaks

[m-pitera]

Description:
Adding solutions to issues discovered in program-intent-engagement repo:

• build: use a docker-compoase build directive rather than public image name edx/program-intent-engagement#9
  • This has docker use a docker-compose.yml build directive instead of from a docker image
  • This edit is made because right now docker won't work without a published image
• build: provisioning tweaks edx/program-intent-engagement#17
  • This is the provisioning tweak changes that resolved an issue with creating docker images on the right path
  • added $repo_name to the provision script so it references the correct paths