Add Graphviz headers

jacebrowning · jacebrowning · commit 461f758c3e80 · 2020-12-22T16:31:18.000-05:00
diff --git a/Dockerfile b/Dockerfile
@@ -37,5 +37,5 @@ geckodriver --version
 
 # Graphviz
 
-RUN sudo apt install graphviz && \
+RUN sudo apt install graphviz graphviz-dev && \
 dot -V
