Don't create default commands if they're already defined (init)

.ahoy.yml

@@ -1,11 +1,11 @@
 ahoyapi: v1
 version: 0.0.0
 commands:
-  i:
-    cmd: "go install ahoy/ahoy.go"
+  install:
+    cmd: "go install"
     usage: Build ahoy using go install.
   test:
-    cmd: "go test ahoy/ahoy.go"
+    cmd: "go test"
     usage: Test out ahoy using go.
   docker:
     #cmd: "ahoy help home"
@@ -14,4 +14,7 @@ commands:
   confirm:
     cmd: "ahoy -f examples/confirmation.ahoy.yml confirm {{args}}"
     usage: Example of importing a single docker command from examples/confirmation.ahoy.yml
-    hidehelp: true
+    hide: true
+  init:
+    cmd: echo ".ahoy.yml file already exists."
+    hide: true

ahoy.go

@@ -173,7 +173,8 @@ func runCommand(name string, c string) {
 }
 
 func addDefaultCommands(commands []cli.Command) []cli.Command {
-	newCmd := cli.Command{
+
+	defaultInitCmd := cli.Command{
 		Name:  "init",
 		Usage: "Initialize a new .ahoy.yml config file in the current directory.",
 		Action: func(c *cli.Context) {
@@ -196,8 +197,10 @@ func addDefaultCommands(commands []cli.Command) []cli.Command {
 		},
 	}
 
-	// TODO: Check if a command has already been set. Don't add defaults if it has.
-	commands = append(commands, newCmd)
+	// Don't add default commands if they've already been set.
+	if c := app.Command(defaultInitCmd.Name); c == nil {
+		commands = append(commands, defaultInitCmd)
+	}
 	return commands
 }