Bump version to 5.21.0

Author: matthid

.config/dotnet-tools.json

@@ -15,7 +15,7 @@
       ]
     },
     "fake-cli": {
-      "version": "5.21.0-alpha004",
+      "version": "1.0.0-1",
       "commands": [
         "fake"
       ]