Update the Travis build to use the dotted formatter.
Update the Travis build to use the dotted formatter.

* For some unknown reason 2.0.0 fails a lot of specs
  when the spinner formatter is used.

iliabylich/rubyspec,askl56/rubyspec,ruby/rubyspec,wied03/rubyspec,sgarciac/spec,nobu/rubyspec,jannishuebl/rubyspec,ruby/spec,lucaspinto/rubyspec,wied03/rubyspec,kachick/rubyspec,sgarciac/spec,kidaa/rubyspec,ruby/spec,ruby/rubyspec,eregon/rubyspec,benlovell/rubyspec,nobu/rubyspec,eregon/rubyspec,askl56/rubyspec,kidaa/rubyspec,bl4ckdu5t/rubyspec,sgarciac/spec,lucaspinto/rubyspec,kachick/rubyspec,bl4ckdu5t/rubyspec,jannishuebl/rubyspec,BanzaiMan/rubyspec,iliabylich/rubyspec,eregon/rubyspec,yous/rubyspec,wied03/rubyspec,kachick/rubyspec,BanzaiMan/rubyspec,nobu/rubyspec,ruby/spec,yous/rubyspec,benlovell/rubyspec