Add safety limits for dependency parsing

Change-Id: If901f9d7f03bc7926a812dfa55bf18a58149e583
diff --git a/Dockerfile b/Dockerfile
index 548bc69..9499173 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -47,6 +47,8 @@
 # spaCy processing configuration
 ENV SPACY_USE_DEPENDENCIES="True"
 ENV SPACY_USE_GERMALEMMA="True"
+ENV SPACY_PARSE_TIMEOUT="30"
+ENV SPACY_MAX_SENTENCE_LENGTH="500"
 
 WORKDIR /app
 RUN mkdir -p "/app/logs"