Remove problematic Map casts

bin/angel.dart

@@ -11,6 +11,9 @@ main(List<String> args) async {
   var runner =
       new CommandRunner("angel", "Command-line tools for the Angel framework.");
 
+  runner.argParser
+      .addFlag('verbose', help: 'Print verbose output', negatable: false);
+
   runner
     ..addCommand(new DoctorCommand())
     ..addCommand(new KeyCommand())
@@ -19,12 +22,16 @@ main(List<String> args) async {
     ..addCommand(new RenameCommand())
     ..addCommand(new MakeCommand());
 
-  return await runner.run(args).then((_) {}).catchError((exc) {
+  return await runner.run(args).then((_) {}).catchError((exc, st) {
     if (exc is String) {
       stdout.writeln(exc);
     } else {
       stderr.writeln("Oops, something went wrong: $exc");
       exitCode = 1;
+
+      if (args.contains('--verbose')) {
+        stderr.writeln(st);
+      }
     }
   });
 }

lib/src/commands/install.dart

@@ -73,7 +73,7 @@ class InstallCommand extends Command {
           throw 'No add-on named "$packageName" is installed. You might need to run `angel install --update`.';
         print('Installing $packageName...');
 
-        Map<String, dynamic> values = {
+        Map values = {
           'project_name': pubspec.name,
           'pubspec': pubspec,
         };
@@ -106,7 +106,7 @@ class InstallCommand extends Command {
         if (await promptFile.exists()) {
           var contents = await promptFile.readAsString();
           var y = yaml.loadYamlDocument(contents);
-          var cfg = y.contents.value as Map<String, dynamic>;
+          var cfg = y.contents.value as Map;
 
           // Loads globs
           if (cfg['templates'] is List) {
@@ -115,7 +115,7 @@ class InstallCommand extends Command {
           }
 
           if (cfg['values'] is Map) {
-            var val = cfg['values'] as Map<String, dynamic>;
+            var val = cfg['values'] as Map;
 
             for (var key in val.keys) {
               var desc = val[key]['description'] ?? key;