Update Hugo to version 0.84.0

Dockerfile

@@ -9,9 +9,9 @@
 # to work around segmentation fault issues.
 FROM golang:1.13-alpine
 ARG HUGO=hugo
-ARG HUGO_VERSION=0.83.1
-ARG HUGO_SHA=5b756314756935e39040bba10867a7340e791e5e87890e0318760258c43e542e
-ARG HUGO_EXTENDED_SHA=7dab678e7bd47de76b311c1dc51257d1ba41d95e8e1d30869f701e1628261447
+ARG HUGO_VERSION=0.84.0
+ARG HUGO_SHA=8779242c38d52faf9b97ccad4cbf527ce701873e4061282ab3ac66fbdbceb79f
+ARG HUGO_EXTENDED_SHA=73a5cf16eb6e4a7a0303100dff5962e39666b4e48047c7033ea9819dd710f804
 RUN set -eux && \
     case ${HUGO} in \
       *_extended) \