Delete opencon-es.jpg
Delete opencon-es.jpg

will replace

Former-commit-id: 8b2d44c0b233f7fb2467c6b90345b0aace682d60 [formerly 2da93740b569ed95aed8bb2b95287938692304fa]
Former-commit-id: 2371f0e515f804c7038754d5a9d829021e6226b2
LibraryCarpentry/librarycarpentry.github.io,LibraryCarpentry/librarycarpentry.github.io,LibraryCarpentry/librarycarpentry.github.io