Patch release with updated dependencies

• Issues with Bolt db, simplebolt and gccgo are resolved. Algernon now also supports gccgo.
• Algernon requires Go 1.11 or later.
• Respect TMPDIR, for improved Termux support.
• Fix issue #42, when --dir is used together with a trailing slash.
• Don't force the use of the bolt database when in development mode.
• Update dependencies.

The Windows and OpenBSD releases does not compile anymore. I want to look into that at some point.