Use "helm" filtype first for vim modeline + tests

"helm" can be managed by vim/neovim plugins, so it's a good idea to add
it as default, then use "gotmpl.yaml".

Add basic tests...

generator/tools_test.go

@@ -0,0 +1,64 @@
+package generator
+
+import (
+	"os/exec"
+	"testing"
+
+	"katenary/parser"
+)
+
+type DeploymentTest struct {
+	Spec struct {
+		Replicas int `yaml:"replicas"`
+		Template struct {
+			Spec struct {
+				Containers []struct {
+					Image string `yaml:"image"`
+				} `yaml:"containers"`
+			} `yaml:"spec"`
+		} `yaml:"template"`
+	} `yaml:"spec"`
+}
+
+func _compile_test(t *testing.T) string {
+	_, err := parser.Parse(nil, "compose.yml")
+	if err != nil {
+		t.Errorf("Failed to parse the project: %s", err)
+	}
+
+	force := false
+	outputDir := "./chart"
+	profiles := make([]string, 0)
+	helmdepUpdate := false
+	var appVersion *string
+	chartVersion := "0.1.0"
+	convertOptions := ConvertOptions{
+		Force:        force,
+		OutputDir:    outputDir,
+		Profiles:     profiles,
+		HelmUpdate:   helmdepUpdate,
+		AppVersion:   appVersion,
+		ChartVersion: chartVersion,
+	}
+	Convert(convertOptions, "compose.yml")
+	// launch helm lint to check the generated chart
+	if helmLint(convertOptions) != nil {
+		t.Errorf("Failed to lint the generated chart")
+	}
+	// try with helm template
+	var output string
+	if output, err = helmTemplate(convertOptions); err != nil {
+		t.Errorf("Failed to template the generated chart")
+		t.Errorf("Output: %s", output)
+	}
+	return output
+}
+
+func helmTemplate(options ConvertOptions) (string, error) {
+	cmd := exec.Command("helm", "template", options.OutputDir)
+	output, err := cmd.CombinedOutput()
+	if err != nil {
+		return string(output), err
+	}
+	return string(output), nil
+}