Remove 'assets' from default target
Remove 'assets' from default target

There are issues with changing timestamps for unmodified files
in go-bindata+git.

tyrken/alertmanager,Kellel/alertmanager,tbouvet/alertmanager,MonsantoCo/alertmanager,sarathsp06/alertmanager,brancz/alertmanager,ericgerling/alertmanager,novilabs/alertmanager,tyrken/alertmanager,MonsantoCo/alertmanager,tinytub/alertmanager,brunoqc/alertmanager,pdf/alertmanager,Kellel/alertmanager,novilabs/alertmanager,GoogleCloudPlatform/alertmanager,tyrken/alertmanager,novilabs/alertmanager,GoogleCloudPlatform/alertmanager,sarathsp06/alertmanager,MonsantoCo/alertmanager,tinytub/alertmanager,MonsantoCo/alertmanager,tbouvet/alertmanager,tyrken/alertmanager,joehandzik/alertmanager,prometheus/alertmanager,brunoqc/alertmanager,Aloomaio/alertmanager,pdf/alertmanager,brunoqc/alertmanager,brunoqc/alertmanager,brancz/alertmanager,tinytub/alertmanager,joehandzik/alertmanager,prometheus/alertmanager,prometheus/alertmanager,Kellel/alertmanager,prometheus/alertmanager,brancz/alertmanager,ericgerling/alertmanager,pdf/alertmanager,brancz/alertmanager,sarathsp06/alertmanager,Aloomaio/alertmanager,novilabs/alertmanager,GoogleCloudPlatform/alertmanager,tbouvet/alertmanager,pdf/alertmanager,joehandzik/alertmanager,ericgerling/alertmanager,Aloomaio/alertmanager,GoogleCloudPlatform/alertmanager