Make version/update checks in dashboard periodic
Make version/update checks in dashboard periodic

This way the user will get easy notification of any updates if using the
dashboard as a status board, and won't need to reload it for the version
to increase.

shrug/puppetdb,ajroetker/puppetdb,grimradical/puppetdb,nfagerlund/puppetdb,melissa/puppetdb,johnduarte/puppetdb,cprice404/puppetdb,kbrezina/puppetdb,nfagerlund/puppetdb,jantman/puppetdb,nfagerlund/puppetdb,waynr/puppetdb,puppetlabs/puppetdb,shrug/puppetdb,mullr/puppetdb,johnduarte/puppetdb,johnduarte/puppetdb,kbrezina/puppetdb,mullr/puppetdb,wkalt/puppetdb,mullr/puppetdb,shrug/puppetdb,grimradical/puppetdb,highb/puppetdb,puppetlabs/puppetdb,senior/puppetdb,rbrw/puppetdb,jantman/puppetdb,kbarber/puppetdb,highb/puppetdb,wkalt/puppetdb,kbarber/puppetdb,rbrw/puppetdb,grimradical/puppetdb,kbrezina/puppetdb,mullr/puppetdb,wkalt/puppetdb,github/puppetlabs-puppetdb,highb/puppetdb,shrug/puppetdb,rbrw/puppetdb,kbrezina/puppetdb,puppetlabs/puppetdb,melissa/puppetdb,cprice404/puppetdb,cprice404/puppetdb,wkalt/puppetdb,senior/puppetdb,mullr/puppetdb,waynr/puppetdb,ajroetker/puppetdb,kbarber/puppetdb,melissa/puppetdb,waynr/puppetdb,kbarber/puppetdb,puppetlabs/puppetdb,jantman/puppetdb,rbrw/puppetdb,github/puppetlabs-puppetdb,senior/puppetdb,johnduarte/puppetdb,highb/puppetdb,ajroetker/puppetdb,github/puppetlabs-puppetdb,grimradical/puppetdb,puppetlabs/puppetdb,senior/puppetdb,ajroetker/puppetdb,waynr/puppetdb,rbrw/puppetdb