Move "Can't find fig.yml" error into errors.py

fig/cli/command.py

@@ -50,11 +50,8 @@ class Command(DocoptCommand):
 
         except IOError as e:
             if e.errno == errno.ENOENT:
-                log.error("Can't find %s. Are you in the right directory?", os.path.basename(e.filename))
-            else:
-                log.error(e)
-
-            sys.exit(1)
+                raise errors.FigFileNotFound(os.path.basename(e.filename))
+            raise errors.UserError(six.text_type(e))
 
         try:
             return Project.from_config(self.project_name, config, self.client)

fig/cli/errors.py

@@ -51,3 +51,10 @@ Couldn't connect to Docker daemon at %s - is it running?
 
 If it's at a non-standard location, specify the URL with the DOCKER_HOST environment variable.
 """ % url)
+
+
+class FigFileNotFound(UserError):
+    def __init__(self, filename):
+        super(FigFileNotFound, self).__init__("""
+Can't find %s. Are you in the right directory?
+""" % filename)