Make it possible to start a sky app in an arbitrary relative path, ra…

…ther than requiring the dart file to be in the current directory.

sky/packages/sky/lib/sky_tool

@@ -248,9 +248,7 @@ class StartSky(object):
             main_dart = os.path.join(project_or_path, 'lib', 'main.dart')
             missing_msg = 'Missing lib/main.dart in project: %s' % project_or_path
         else:
-            # FIXME: This assumes the path is at the root of the project!
-            # Instead we should walk up looking for a pubspec.yaml
-            sky_server_root = os.path.dirname(project_or_path)
+            sky_server_root = os.getcwd()
             main_dart = project_or_path
             missing_msg = '%s does not exist.' % main_dart