Remove nodejs install if it exists

src/freedombone-utils-nodejs

     echo "deb-src https://deb.nodesource.com/node_6.x jessie main" >> /etc/apt/sources.list.d/nodesource.list
 
     apt-get update
+
+    if [ -f /usr/bin/nodejs ]; then
+        apt-get -yq remove --purge nodejs
+    fi
+    if [ -d /usr/local/lib/node_modules ]; then
+        rm -rf /usr/local/lib/node_modules
+    fi
+
     apt-get -yq install nodejs curl
 
     if [ ! -f /usr/bin/nodejs ]; then