dashboard: tell perf dashboard about release 1.4
dashboard: tell perf dashboard about release 1.4

Change-Id: I074b12a155278cb2a53414cd1f9abf650df8e89d
Reviewed-on: https://go-review.googlesource.com/1381
Reviewed-by: Andrew Gerrand <395a7d33bec8475c9b83b7d440f141bcbd994aa5@golang.org>

jdhenke/tools,syreclabs/go-tools,josharian/tools,dmitris/tools,4ad/tools,magiccao/tools,syreclabs/go-tools,golang/tools,cw2018/tools,glasser/golang-tools,runcom/tools,syreclabs/go-tools,nicot/tools,magiccao/tools,glasser/golang-tools,runcom/tools,maddyonline/tools,argandas/tools,jdhenke/tools,cw2018/tools,sshetty10/tools,matryer/tools,sshetty10/tools,maddyonline/tools,jdhenke/tools,springning/tools,glasser/golang-tools,syreclabs/go-tools,cmars/tools,maddyonline/tools,springning/tools,magiccao/tools,dmitris/tools,sshetty10/tools,dmitris/tools,sshetty10/tools,dmitris/tools,nicot/tools,matryer/tools,josharian/tools,jdhenke/tools,cmars/tools,syreclabs/go-tools,4ad/tools,nicot/tools,argandas/tools,matryer/tools,josharian/tools,josharian/tools,argandas/tools,golang/tools,golang/tools,springning/tools,cmars/tools,springning/tools,runcom/tools,syreclabs/go-tools,argandas/tools,cw2018/tools,nicot/tools,4ad/tools,magiccao/tools,cmars/tools,golang/tools,golang/tools,runcom/tools,matryer/tools,cw2018/tools,glasser/golang-tools,maddyonline/tools