Refactor e2e tests

Signed-off-by: Stefan Prodan <stefan.prodan@gmail.com>

cmd/flux/version_test.go

@@ -0,0 +1,15 @@
+// +build unit
+
+package main
+
+import (
+	"testing"
+)
+
+func TestVersion(t *testing.T) {
+	cmd := cmdTestCase{
+		args:        "--version",
+		goldenValue: "flux version 0.0.0-dev.0\n",
+	}
+	cmd.runTestCmd(t)
+}