[ci fw-only D/hunt] remove hunt application binary (#3562)

The "website" file is what hunt generates during its build process.  We
don't need it in source control.

frameworks/D/hunt/hunt.dockerfile

@@ -1,10 +1,12 @@
 FROM dlanguage/ldc:1.7.0
 
-ADD ./ /hunt
 WORKDIR /hunt
+COPY config config
+COPY source source
+COPY dub.json dub.json
+COPY dub.selections.json dub.selections.json
 
 RUN dub upgrade --verbose
-
 RUN dub build -f -b release -v
 
 CMD ["./website"]