Add checkout method

vars/checkoutStep.groovy

@@ -0,0 +1,16 @@
+#!/usr/bin/env groovy
+
+String call(Map config = [:]) {
+    Map defaults = [
+        dirtyFlag: '-dirty'
+    ]
+    Map runConfig = defaults + config
+
+    checkout scm
+
+    GIT_TAG = sh(
+        script: "git describe --tags --always --dirty=${runConfig.dirtyFlag}",
+        returnStdout: true
+      ).trim()
+    return GIT_TAG
+}

vars/packageStep.groovy

@@ -0,0 +1,10 @@
+#!/usr/bin/env groovy
+
+void call(Map config = [:]) {
+    Map defaults = [
+        artifacts: []
+    ]
+    Map runConfig = defaults + config
+
+    echo "${runConfig}"
+}