Update branch metadata

Branches have been renamed to be consistent with other Doctrine
repositories.

Author: greg0ire

.doctrine-project.json

@@ -5,15 +5,15 @@
     "docsSlug": "doctrine-phpcr-odm",
     "versions": [
         {
-            "name": "2.x",
-            "branchName": "2.x",
+            "name": "2.0",
+            "branchName": "2.0.x",
             "slug": "latest",
             "current": true
         },
         {
-            "name": "1.x",
-            "branchName": "1.x",
-            "slug": "1.x",
+            "name": "1.5",
+            "branchName": "1.5.x",
+            "slug": "1.5",
             "maintained": true
         }
     ]