Miami hangover

What's Changed

• Dynamic fee limits by @skosito in #136
• add favicon.ico rewrite by @kiwiidb in #145
• Add and use expected requests and responses for integration tests by @skosito in #147
• Feature/metrics by @kiwiidb in #142
• Do not send bad auth errors to sentry by @skosito in #146
• always lowercase payreq by @kiwiidb in #149
• always build docker images on every branch by @kiwiidb in #148

Full Changelog: 0.4.1...0.5.0