new icon: codecov (plain) (#649)

* Add Codecov icons (plain)

* Update codecov-plain

* Centered codecov plain

Co-authored-by: Raúl Julián López Caña <rjlopezmad@gmail.com>
Co-authored-by: Clemens Bastian <8781699+amacado@users.noreply.github.com>

Author: 3 people

devicon.json

@@ -556,6 +556,16 @@
         "color": "#96ca4b",
         "aliases": []
     },
+    {
+        "name": "codecov",
+        "tags": ["platform", "integration"],
+        "versions": {
+          "svg": ["plain"],
+          "font": ["plain"]
+        },
+        "color": "#e0225c",
+        "aliases": []
+    },
     {
         "name": "codeigniter",
         "tags": [