Add inventory plugins for buildah and podman (#963)

Add inventory plugins for buildah and podman, unit tests and functional CI tests.
---------

Signed-off-by: Sagi Shnaidman <sshnaidm@redhat.com>

playbooks/examples/go_app/main.go

@@ -0,0 +1,19 @@
+package main
+
+import (
+    "fmt"
+    "math/rand"
+    "net/http"
+)
+
+func predict(w http.ResponseWriter, r *http.Request) {
+    fmt.Fprintf(w, "prediction=%f\n", rand.Float64())
+}
+
+func main() {
+    http.HandleFunc("/predict", predict)
+    fmt.Println("Inference engine listening on :8080")
+    http.ListenAndServe(":8080", nil)
+}
+
+