Don't cache index.html (#675)
Don't cache index.html (#675)

Part of dockstore/dockstore-ui2#2447

We don't want browser to cache index.html; when we
do a new a release, we want latest index.html to be
fetched.
dockstore/dockstore-ui2,dockstore/dockstore-ui2,dockstore/dockstore-ui2,dockstore/dockstore-ui2