Strip extra escape codes on empty lines

Signed-off-by: Peter Hyatt <peter.hyatt@gmail.com>

docker/models/images.py

@@ -317,7 +317,7 @@ def build(self, stream=False, timestamp=False, **kwargs):
  if 'stream' in chunk:
  if stream:
  for line in chunk["stream"].splitlines():
- if len(line.strip()) > 0:
+ if len(line.strip()) > 0 and not bool(re.match(r'^(\s*\x1b\[[0-9;]*m)*\s*(\x1b\[0m)?\s*$', line.strip())):
  if timestamp:
  print(timestamp_str, "- ", end='')
  print(line.strip(), flush=True)