Remove unused imports
There are several imports that are not used. Remove them.
Change-Id: I2ac3be66827bd68d3faedcef7d6bbf30ea01d3f2
diff --git a/project.py b/project.py
index 00ebb17..06baccb 100644
--- a/project.py
+++ b/project.py
@@ -27,10 +27,8 @@
from color import Coloring
from git_command import GitCommand
from git_config import GitConfig, IsId, GetSchemeFromUrl, ID_RE
-from error import DownloadError
-from error import GitError, HookError, ImportError, UploadError
+from error import GitError, HookError, UploadError
from error import ManifestInvalidRevisionError
-from progress import Progress
from trace import IsTrace, Trace
from git_refs import GitRefs, HEAD, R_HEADS, R_TAGS, R_PUB, R_M