new icon: elixir (original, original-wordmark, plain, plain-wordmark) (#500)

* new icon: elixir (original, original-wordmark, plain, plain-wordmark)
* Fix elixir svg style declaration

Author: maltejur

devicon.json

@@ -932,6 +932,16 @@
       "color": "#1f1f1f",
       "aliases": []
     },
+    {
+        "name": "elixir",
+        "tags": "language",
+        "versions": {
+            "svg": ["original", "original-wordmark", "plain", "plain-wordmark"],
+            "font": ["plain", "plain-wordmark"]
+        },
+        "color": "#380A4D",
+        "aliases": []
+    },
     {
         "name": "elm",
         "tags": [