🐛 Update to ocrd >= 2.21.0 for a fix for OCR-D/core#642

Dockerfile-core

@@ -1,7 +1,7 @@
 FROM ubuntu:18.04
 
 ARG PIP_INSTALL="pip install --no-cache-dir --use-feature=2020-resolver"
-ARG OCRD_VERSION_MINIMUM="2.18.1"
+ARG OCRD_VERSION_MINIMUM="2.21.0"
 ENV LC_ALL=C.UTF-8 LANG=C.UTF-8
 ENV PIP_DEFAULT_TIMEOUT=120
 

Dockerfile-ocrd_calamari

@@ -20,8 +20,7 @@ COPY data/mirror/github.com/Calamari-OCR/calamari_models/gt4histocr
 
 
 # Check pip dependencies
-# XXX https://github.com/OCR-D/core/issues/642
-#RUN pip check
+RUN pip check
 
 
 # Default command