Fix nightly by updating .cache in dockerignore (huggingface#464)

Author: Cadene

.dockerignore

@@ -65,14 +65,18 @@ htmlcov/
 .nox/
 .coverage
 .coverage.*
-.cache
 nosetests.xml
 coverage.xml
 *.cover
 *.py,cover
 .hypothesis/
 .pytest_cache/
 
+# Ignore .cache except calibration
+.cache/*
+!.cache/calibration/
+!.cache/calibration/**
+
 # Translations
 *.mo
 *.pot