gnu: Add elixir-phoenix-live-favicon.

* gnu/packages/elixir-web.scm (elixir-phoenix-live-favicon): New variable.

Change-Id: Ie1232a938764790d7fd6b4afde5a4f9e11ecff93
Signed-off-by: Ludovic Courtès <ludo@gnu.org>

gnu/packages/elixir-web.scm

@@ -428,6 +428,27 @@ framework.")
     (home-page "https://hexdocs.pm/phoenix_html/")
     (license license:expat)))
 
+(define-public elixir-phoenix-live-favicon
+  (package
+    (name "elixir-phoenix-live-favicon")
+    (version "0.2.0")
+    (source
+     (origin
+       (method url-fetch)
+       (uri (hexpm-uri "phoenix_live_favicon" version))
+       (sha256
+        (base32 "17m7gpx6qw0cr0d2acwajjhz2qzfi2zywzyk2i139y9higb22q8k"))))
+    (build-system mix-build-system)
+    (arguments
+     ;; Tests depend on makeup_diff from hex.pm but it is not packaged yet.
+     (list #:tests? #f))
+    (propagated-inputs (list elixir-phoenix-live-head))
+    (synopsis "Favicon manipulation for Phoenix Live Views")
+    (description "This package provides a lib enabling dynamic favicons in
+Phoenix Live View applications.")
+    (home-page "https://hexdocs.pm/phoenix_live_favicon/")
+    (license license:expat)))
+
 (define-public elixir-phoenix-live-head
   (package
     (name "elixir-phoenix-live-head")