test: add github test environment action

Create a github action that accepts any command with args and runs
it in a container that is prepared with all the dependencies for
koji (hub, builder, command line), so all tests, like pylint or
unit tests can run in it.

test/Dockerfile

@@ -0,0 +1,21 @@
+FROM docker.io/library/fedora:latest
+
+RUN dnf -y upgrade \
+    && dnf -y \
+            --setopt=fastestmirror=True \
+            --setopt=install_weak_deps=False \
+            install \
+	koji-builder \
+	koji-hub \
+	koji-utils \
+	koji \
+	postgresql \
+	pylint \
+	python3-flexmock \
+	python3-jsonschema \
+	python3-koji \
+	&& dnf clean all
+
+COPY entrypoint.sh /entrypoint.sh
+
+ENTRYPOINT ["/entrypoint.sh"]

test/action.yml

@@ -0,0 +1,12 @@
+name: 'Koji plugin test environment'
+description: 'Environment prepared for running koji plugin tests'
+inputs:
+  run:
+    description: 'What to run'
+    required: true
+    default: 'echo "Nothing to do"'
+runs:
+  using: 'docker'
+  image: 'Dockerfile'
+  args:
+    - ${{ inputs.run }}

test/entrypoint.sh

@@ -0,0 +1,6 @@
+#!/bin/sh -l
+set -euo pipefail
+
+cd $GITHUB_WORKSPACE
+
+/bin/bash -o errexit -c "$1"