WIP Adding native support for docker.

src/test/json/dummy-project.config.json

@@ -1,8 +1,10 @@
 {
   "name": "dummy-project",
   "versionCmd": "git describe --all --always",
+  "containerImage": "ubuntu",
   "steps": {
     "build": {
+      "containerImage": "alpine",
       "depends": ["test"],
       "workingDir": "dir1",
       "stepCmd": "cust-build",

src/test/nim/unit/tconfiguration.nim

@@ -99,6 +99,7 @@ suite "load and save configuration objects":
     check:
       pc.name == "dummy-project"
       pc.versionCmd == "git describe --all --always"
+      pc.containerImage == "ubuntu"
       pc.steps.len == 2
 
       # Explicitly set properties
@@ -106,6 +107,7 @@ suite "load and save configuration objects":
       pc.steps["build"].dontSkip == true
       pc.steps["build"].stepCmd == "cust-build"
       pc.steps["build"].workingDir == "dir1"
+      pc.steps["containerImage"] == "alpine"
       sameContents(pc.steps["build"].artifacts, @["bin1", "doc1"])
       sameContents(pc.steps["build"].depends, @["test"])
       sameContents(pc.steps["build"].expectedEnv, @["VAR1"])
@@ -115,7 +117,8 @@ suite "load and save configuration objects":
       pc.steps["test"].name == "test"
       pc.steps["test"].dontSkip == false
       pc.steps["test"].stepCmd == "true"
-      pc.steps["test"].workingDir == "."
+      pc.steps["test"].workingDir == ".:
+      pc.steps["test"].containerImage.isNilOrEmpty
       sameContents(pc.steps["test"].artifacts, @[])
       sameContents(pc.steps["test"].depends, @[])
       sameContents(pc.steps["test"].expectedEnv, @[])