Additions

• Add support for Sendgrid unique arguments (#609)
• Accept timeout option in test helpers (#605)
• Add assign/2 to Bamboo.Template to set many assigns (#600)

Fixes/Enhancements

• Set default timeout in test helpers to 100 (#607)
• Turn some test helpers from macros -> functions (#604)
• Use refute_timeout configured for all refute_ assertions (#603)
• Organize Bamboo's TestAdapter test file (#601)
• fix deliver_later typo (#598)
• Fix typo: Bambooo -> Bamboo (#597)