modificando condicion de tags, se requiere que campos no requeridos no sean vacios en el validador de twitter
Merge branch 'og-twitter-card' into staging-production

Conflicts:
	telesur/theme/browser.py
        Generated by a new line in the file.

	telesur/theme/jbot/plonetheme.sunburst.skins.sunburst_templates.main_template.pt
        This file don't exist previously, but was removed from a previous merge.