Templates failing validation.

[F21]

A large amount of templates in the repository are failing validation. I only tested a few in the repo, but here are some of the validation errors:

black-friday.mjml
- Line 2 of (mj-body) - Attributes color, font-family are illegal
- Line 3 of (mj-section) - Attribute vertical-align is illegal
- Line 11 of (mj-section) - Attribute vertical-align is illegal
- Line 16 of (mj-section) - Attribute vertical-align is illegal
- Line 26 of (mj-section) - Attribute vertical-align is illegal

one-page.mjml
- Line 13 of (mj-image) - Attribute padding-top has invalid value: 10 for type Unit, only accepts (px, %) units and 1 value(s)
- Line 16 of (mj-text) - Attribute padding-top has invalid value: 10 for type Unit, only accepts (px, %) units and 1 value(s)
- Line 22 of (mj-section) - Attribute vertical-align is illegal
- Line 24 of (mj-text) - Attribute padding-top has invalid value: 45 for type Unit, only accepts (px, %) units and 1 value(s)
- Line 25 of (mj-button) - Attribute padding-top has invalid value: 10 for type Unit, only accepts (px, %) units and 1 value(s)
- Line 29 of (mj-section) - Attribute vertical-align is illegal
- Line 32 of (mj-text) - Attribute padding-top has invalid value: 20 for type Unit, only accepts (px, %) units and 1 value(s)
- Line 36 of (mj-text) - Attribute padding-top has invalid value: 20 for type Unit, only accepts (px, %) units and 1 value(s)
- Line 40 of (mj-text) - Attribute padding-top has invalid value: 20 for type Unit, only accepts (px, %) units and 1 value(s)
- Line 43 of (mj-section) - Attribute vertical-align is illegal
- Line 45 of (mj-text) - Attribute padding-top has invalid value: 25 for type Unit, only accepts (px, %) units and 1 value(s)
- Line 46 of (mj-divider) - Attribute padding-top has invalid value: 20 for type Unit, only accepts (px, %) units and 1 value(s)
- Line 47 of (mj-text) - Attribute padding-top has invalid value: 20 for type Unit, only accepts (px, %) units and 1 value(s)
- Line 51 of (mj-section) - Attribute vertical-align is illegal
- Line 53 of (mj-image) - Attribute padding-top has invalid value: 20 for type Unit, only accepts (px, %) units and 1 value(s)
- Line 56 of (mj-text) - Attribute padding-top has invalid value: 25 for type Unit, only accepts (px, %) units and 1 value(s)
- Line 58 of (mj-button) - Attribute padding-top has invalid value: 10 for type Unit, only accepts (px, %) units and 1 value(s)

real-estate.mjml
- Line 31 of (mj-section) - Attribute vertical-align is illegal
- Line 100 of (mj-section) - Attribute vertical-align is illegal

receipt-email.mjml
- Line 2 of (mj-body) - Attribute font-size is illegal
- Line 3 of (mj-section) - Attribute padding-top has invalid value: 20 for type Unit, only accepts (px, %) units and 1 value(s)
- Line 5 of (mj-image) - Attribute padding-top has invalid value: 10 for type Unit, only accepts (px, %) units and 1 value(s)
- Line 15 of (mj-text) - Attribute padding-top has invalid value: 10 for type Unit, only accepts (px, %) units and 1 value(s)
- Line 23 of (mj-text) - Attribute padding-top has invalid value: 10 for type Unit, only accepts (px, %) units and 1 value(s)
- Line 28 of (mj-section) - Attribute padding-top has invalid value: 15 for type Unit, only accepts (px, %) units and 1 value(s)
- Line 30 of (mj-text) - Attribute padding-top has invalid value: 20 for type Unit, only accepts (px, %) units and 1 value(s)
- Line 31 of (mj-text) - Attribute padding-top has invalid value: 10 for type Unit, only accepts (px, %) units and 1 value(s)
- Line 34 of (mj-text) - Attribute padding-top has invalid value: 20 for type Unit, only accepts (px, %) units and 1 value(s)
- Line 35 of (mj-text) - Attribute padding-top has invalid value: 10 for type Unit, only accepts (px, %) units and 1 value(s)
- Line 38 of (mj-text) - Attribute padding-top has invalid value: 20 for type Unit, only accepts (px, %) units and 1 value(s)
- Line 39 of (mj-text) - Attribute padding-top has invalid value: 10 for type Unit, only accepts (px, %) units and 1 value(s)
- Line 42 of (mj-section) - Attribute padding-top has invalid value: 20 for type Unit, only accepts (px, %) units and 1 value(s)
- Line 44 of (mj-button) - Attribute padding-top has invalid value: 10 for type Unit, only accepts (px, %) units and 1 value(s)
- Line 48 of (mj-button) - Attribute padding-top has invalid value: 10 for type Unit, only accepts (px, %) units and 1 value(s)
- Line 55 of (mj-text) - Attribute padding-top has invalid value: 10 for type Unit, only accepts (px, %) units and 1 value(s)

Maybe the templates should be updated so that they pass validation? It looks like there are some PRs to fix some of these: #12 and #13.