v1.14.0-ls57

LinuxServer Changes:

Rebasing to alpine 3.11.
healthchecks Changes:

Improvements

• Improved UI to invite users from account's other projects (#258)
• Experimental Prometheus metrics endpoint (#300)
• Don't store user's current project in DB, put it explicitly in page URLs (#336)
• API reference in Markdown
• Use Selectize.js for entering tags (#324)
• Zulip integration (#202)
• OpsGenie integration returns more detailed error messages
• Telegram integration returns more detailed error messages
• Added the "Get a single check" API call (#337)
• Display project name in Slack notifications (#342)

Bug Fixes

• The "render_docs" command checks if markdown and pygments is installed (#329)
• The team size limit is applied to the n. of distinct users across all projects (#332)
• API: don't let SuspiciousOperation bubble up when validating channel ids
• API security: check channel ownership when setting check's channels
• API: update check's "alert_after" field when changing schedule
• API: validate channel identifiers before creating/updating a check (#335)
• Fix redirect after login when adding Telegram integration