Use hugo 0.87's date formatting feature with time.Format (#555)

Author: Saxodwarf

layouts/partials/post_meta.html

@@ -1,7 +1,7 @@
 {{- $scratch := newScratch }}
 
 {{- if not .Date.IsZero -}}
-{{- $scratch.Add "meta" (slice (printf "<span title='%s'>%s</span>" (.Date) (.Date.Format (default "January 2, 2006" .Site.Params.DateFormat)))) }}
+{{- $scratch.Add "meta" (slice (printf "<span title='%s'>%s</span>" (.Date) (.Date | time.Format (default "January 2, 2006" .Site.Params.DateFormat)))) }}
 {{- end }}
 
 {{- if (.Param "ShowReadingTime") -}}