Convert validation from joi to yup

Merges #178

• Convert validation from joi to yup

Replace lodash/pickBy in pipeline/build.js

Merges #162

• Replaces Lodash with native JS functions.
• Lodash was removed in #150 but was still used in pipeline/build.js.
• Resolves #154.

v2.26.0

Remove Day.js dependency (#151)

v2.25.0

Remove Lodash dependency (#150)

v2.24.0

Replace Moment.js with dayjs

v2.23.0

• Improve location formatting per #147.
• Update dependencies.

v2.22.0

• Support X-WR-CALNAME attribute on vCalendar

v2.21.0

• Support CREATED attribute
• Support LAST-MODIFIED attribute
• Format seconds rather than hardcoding 00

v2.20.0

• Changes how Joi's validate method is called, together with defaulting error to null to keep backwards compatibility
• Adjusts validation error messages, as they changed for array validation.
• Disables Joi's TLD validation for emails

Update dependencies

v2.18.0

update dependencies; bump version