Include dat in scuttlebot install

src/freedombone-app-scuttlebot

     cat <<EOF > $rootdir/usr/bin/install_scuttlebot
 #!/bin/bash
 npm install --arch=$NPM_ARCH -g scuttlebot@${SCUTTLEBOT_VERSION}
+npm install --arch=$NPM_ARCH -g dat
 npm install --arch=$NPM_ARCH -g git-ssb
 npm install --arch=$NPM_ARCH -g git-remote-ssb
 EOF
         exit 528253
     fi
 
+    npm install -g dat
     npm install -g git-ssb
     npm install -g git-remote-ssb