rosenthal: Add go-github-com-emvi-logbuch.

* rosenthal/packages/golang.scm (go-github-com-emvi-logbuch): New variable.

rosenthal/packages/golang.scm

@@ -59,6 +59,30 @@ util function library of Go.  Inspired by the java apache common package and
 lodash.js.")
     (license license:expat)))
 
+(define-public go-github-com-emvi-logbuch
+  (package
+    (name "go-github-com-emvi-logbuch")
+    (version "1.2.0")
+    (source (origin
+              (method git-fetch)
+              (uri (git-reference
+                    (url "https://github.com/emvi/logbuch")
+                    (commit (string-append "v" version))))
+              (file-name (git-file-name name version))
+              (sha256
+               (base32
+                "1l2pn19m04rbx1lzhknyqr0vvcqn7x4qmrgnj4cx80q666mybd9y"))))
+    (build-system go-build-system)
+    (arguments
+     '(#:import-path "github.com/emvi/logbuch"))
+    (home-page "https://github.com/emvi/logbuch")
+    (synopsis "Logbuch")
+    (description
+     "Simple Go logging library with support for different output channels
+(io.Writer) for each log level.  A formatter can be provided to change the log
+output formatting.")
+    (license license:expat)))
+
 (define-public go-github-com-google-gopacket
   (package
     (name "go-github-com-google-gopacket")