Display oldest build date in versions view.
Display oldest build date in versions view.

It says, "X versions since..." the newest build date, but it should
display the oldest one.

Signed-off-by: Nick Quaranto <75ef9faee755c70589550b513ad881e5a603182c@quaran.to>

dstrctrng/private_event,square/rubygems.org,1337807/rubygems.org,1337807/rubygems.org,rubygems/rubygems.org-backup,alloy/gemcutter,1337807/rubygems.org,rubygems/rubygems.org-backup,square/rubygems.org,bpm/getbpm.org,bpm/getbpm.org,dstrctrng/private_event,square/rubygems.org,alloy/gemcutter,rubygems/rubygems.org-backup