feat:(gradle) allow jx create spring to create gradle projects

can either use:
```
jx create spring -x
```
to get prompted for the project types or add
```
jx create spring --type gradle-project
```

see jenkins-x#462
requires this PR to also merge: jenkins-x/draft-packs#9

pkg/jx/cmd/create_spring.go

@@ -29,6 +29,12 @@ var (
 
 		# Creates a Spring Boot application passing in the required dependencies
 		jx create spring -d web -d actuator
+
+		# To pick the advanced options (such as what package type maven-project/gradle-project) etc then use
+		jx create spring -x
+
+		# To create a gradle project use:
+		jx create spring --type gradle-project
 	`)
 )
 
@@ -78,6 +84,7 @@ func NewCmdCreateSpring(f cmdutil.Factory, out io.Writer, errOut io.Writer) *cob
 	cmd.Flags().StringVarP(&options.SpringForm.BootVersion, spring.OptionBootVersion, "t", "", "Spring Boot version")
 	cmd.Flags().StringVarP(&options.SpringForm.JavaVersion, spring.OptionJavaVersion, "j", "", "Java version")
 	cmd.Flags().StringVarP(&options.SpringForm.Packaging, spring.OptionPackaging, "p", "", "Packaging")
+	cmd.Flags().StringVarP(&options.SpringForm.Type, spring.OptionType, "", "", "Project Type (such as maven-project or gradle-project)")
 
 	return cmd
 }

pkg/jx/cmd/import.go

@@ -338,7 +338,12 @@ func (o *ImportOptions) DraftCreate() error {
 	}
 	lpack := ""
 	if exists {
-		lpack = filepath.Join(draftHome.Packs(), "github.com/jenkins-x/draft-packs/packs/java")
+		lpack = filepath.Join(draftHome.Packs(), "github.com/jenkins-x/draft-packs/packs/maven")
+
+		exists, _ = util.FileExists(lpack)
+		if !exists {
+			lpack = filepath.Join(draftHome.Packs(), "github.com/jenkins-x/draft-packs/packs/java")
+		}
 	} else {
 		// pack detection time
 		lpack, err = jxdraft.DoPackDetection(draftHome, o.Out, dir)
@@ -710,47 +715,21 @@ func (o *ImportOptions) checkChartmuseumCredentialExists() error {
 func (o *ImportOptions) renameChartToMatchAppName() error {
 	var oldChartsDir string
 	dir := o.Dir
-	if err := filepath.Walk(dir, func(f string, fi os.FileInfo, err error) error {
-		if fi.Name() == ".git" {
-			return filepath.SkipDir
-		}
+	chartsDir := filepath.Join(dir, "charts")
+	files, err := ioutil.ReadDir(chartsDir)
+	if err != nil {
+		return fmt.Errorf("error matching a jenkins x draft pack name with chart folder %v", err)
+	}
+	for _, fi := range files {
 		if fi.IsDir() {
-			switch fi.Name() {
-			case "csharp":
-				oldChartsDir = filepath.Join(dir, "charts", "csharp")
-				break
-			case "go":
-				oldChartsDir = filepath.Join(dir, "charts", "go")
-				break
-			case "gradle":
-				oldChartsDir = filepath.Join(dir, "charts", "gradle")
-				break
-			case "java":
-				oldChartsDir = filepath.Join(dir, "charts", "java")
-				break
-			case "javascript":
-				oldChartsDir = filepath.Join(dir, "charts", "javascript")
-				break
-			case "php":
-				oldChartsDir = filepath.Join(dir, "charts", "php")
-				break
-			case "python":
-				oldChartsDir = filepath.Join(dir, "charts", "python")
-				break
-			case "ruby":
-				oldChartsDir = filepath.Join(dir, "charts", "ruby")
-				break
-			case "swift":
-				oldChartsDir = filepath.Join(dir, "charts", "swift")
+			name := fi.Name()
+			// TODO we maybe need to try check if the sub dir named after the build pack matches first?
+			if name != "preview" && name != ".git" {
+				oldChartsDir = filepath.Join(chartsDir, name)
 				break
 			}
 		}
-		return nil
-
-	}); err != nil {
-		return fmt.Errorf("error matching a jenkins x draft pack name with chart folder %v", err)
 	}
-
 	if oldChartsDir != "" {
 		// chart expects folder name to be the same as app name
 		newChartsDir := filepath.Join(dir, "charts", o.AppName)

pkg/spring/model.go

@@ -24,6 +24,7 @@ const (
 	OptionPackaging      = "packaging"
 	OptionDependency     = "dep"
 	OptionDependencyKind = "kind"
+	OptionType           = "type"
 
 	startSpringURL = "http://start.spring.io"
 )
@@ -65,6 +66,7 @@ type SpringBootModel struct {
 	Language     SpringOptions
 	JavaVersion  SpringOptions
 	BootVersion  SpringOptions
+	Type         SpringOptions
 	GroupId      SpringValue
 	ArtifactId   SpringValue
 	Version      SpringValue
@@ -86,6 +88,7 @@ type SpringBootForm struct {
 	PackageName     string
 	Dependencies    []string
 	DependencyKinds []string
+	Type            string
 }
 
 func LoadSpringBoot(cacheDir string) (*SpringBootModel, error) {
@@ -118,6 +121,24 @@ func LoadSpringBoot(cacheDir string) (*SpringBootModel, error) {
 	if err != nil {
 		return nil, err
 	}
+	// default the build tool
+	if model.Type.Default == "" {
+		model.Type.Default = "maven"
+	}
+	if len(model.Type.Values) == 0 {
+		model.Type.Values = []SpringOption{
+			{
+				ID:          "gradle",
+				Name:        "Gradle",
+				Description: "Build with the gradle build tool",
+			},
+			{
+				ID:          "maven",
+				Name:        "Maven",
+				Description: "Build with the maven build tool",
+			},
+		}
+	}
 	return &model, nil
 }
 
@@ -159,6 +180,9 @@ func (model *SpringBootModel) CreateSurvey(data *SpringBootForm, advanced bool,
 	if data.Packaging == "" && advanced {
 		qs = append(qs, CreateValueSelect("Packaging", "packaging", &model.Packaging, data))
 	}
+	if data.Type == "" && advanced {
+		qs = append(qs, CreateValueSelect("Build Tool", "type", &model.Type, data))
+	}
 	if data.GroupId == "" {
 		qs = append(qs, CreateValueInput("Group", "groupId", &model.GroupId, data))
 	}
@@ -343,6 +367,7 @@ func (data *SpringBootForm) AddFormValues(form *url.Values) {
 	AddFormValue(form, "artifactId", data.ArtifactId)
 	AddFormValue(form, "version", data.Version)
 	AddFormValue(form, "name", data.Name)
+	AddFormValue(form, "type", data.Type)
 	AddFormValues(form, "dependencies", data.Dependencies)
 }