MailHog v0.1.8

• Add MailHog sendmail shortcut to mhsendmail
• Add #40 - HTTP basic authentication
• Add #63 - message size in UI
• Fix mailhog/MailHog-UI#10 - fix delete for in-memory storage
• Merge mailhog/MailHog-UI#8 - fix styles for .content positioning, thanks @thejameskyle
• Merge mailhog/MailHog-UI#9 - fix content types, thanks @danielwhite
• Merge mailhog/data#4 - factor out use of log package, thanks @ishbir