test: adds tests for container/monorepo and container/polirepo

##### USAGE #####

# TODO: move to readme?

# by default, no job will run.

# the user needs to define manually a kaniko job and a grype job for each of his container images

# kaniko:image_A:

#   extends: .kaniko:monorepo:

#   variables:

#     CONTEXT_PATH: directory_A

# kaniko:image_B:

#   extends: .kaniko:monorepo:

#   variables:

#     CONTEXT_PATH: directory_B

# grype:image_A:

#   extends: .grype:monorepo

#   variables:

#     GRYPE_CONTEXT: directory_A

#   needs: ["kaniko:image_A"]

# grype:image_B:

#   extends: .grype:monorepo

#   variables:

#     GRYPE_CONTEXT: directory_B

#   needs: ["kaniko:image_B"]

# see tests/pipelines/container/monorepo.yml for an example

FROM alpine

RUN touch A

COPY test_A.txt .

FROM alpine

RUN touch B

COPY test_B.txt .