Change command name to migrate

Sources/XcodeGenCLI/Commands/MigrateCommand.swift

@@ -6,8 +6,8 @@ import XcodeGenKit
 import XcodeProj
 import Yams
 
-class GenerateSpecCommand: Command {
-    let name: String = "generate-spec"
+class MigrateCommand: Command {
+    let name: String = "migrate"
 
     let projectFile = Key<Path>("-p", "--project", description: "The path to the project file")
 

Sources/XcodeGenCLI/XcodeGenCLI.swift

@@ -8,7 +8,7 @@ public class XcodeGenCLI {
 
     public init(version: Version) {
         let generateCommand = GenerateCommand(version: version)
-        let specGenerationCommand = GenerateSpecCommand()
+        let migrateCommand = MigrateCommand()
 
         cli = CLI(
             name: "xcodegen",
@@ -17,7 +17,7 @@ public class XcodeGenCLI {
             commands: [
                 generateCommand,
                 DumpCommand(version: version),
-                specGenerationCommand
+                migrateCommand
             ]
         )
         cli.parser.routeBehavior = .searchWithFallback(generateCommand)