Make composer generate a classmap

This enables the package to be autoloaded.

Author: gartner

composer.json

@@ -1,3 +1,6 @@
 {
-    "name": "kbjr/Git.php"
+    "name": "gartner/Git.php",
+    "autoload": {
+        "classmap": ["Git.php"]
+    }
 }