pep-426: properly escape backslashes

pep-0426/pymeta-schema.json

@@ -7,7 +7,7 @@
     "metadata_version": {
       "description": "Version of the file format",
       "type": "string",
-      "pattern": "^(\d+(\.\d+)*)$"
+      "pattern": "^(\\d+(\\.\\d+)*)$"
     },
     "name": {
       "description": "The name of the distribution.",
@@ -17,7 +17,7 @@
     "version": {
       "description": "The distribution's public version identifier",
       "type": "string",
-      "pattern": "^(\d+(\.\d+)*)((a|b|c|rc)(\d+))?(\.(post)(\d+))?(\.(dev)(\d+))?$"
+      "pattern": "^(\\d+(\\.\\d+)*)((a|b|c|rc)(\\d+))?(\\.(post)(\\d+))?(\\.(dev)(\\d+))?$"
     },
     "source_label": {
       "description": "A constrained identifying text string",