Set version to '16.8-alpha'

version.json

@@ -1,9 +1,9 @@
 {
   "$schema": "https://raw.githubusercontent.com/AArnott/Nerdbank.GitVersioning/master/src/NerdBank.GitVersioning/version.schema.json",
-  "version": "16.7",
+  "version": "16.8-alpha",
   "assemblyVersion": "15.3",
   "publicReleaseRefSpec": [
-    "^refs/heads/master$", // we release out of master
-    "^refs/heads/v\\d+(?:\\.\\d+)?$" // we also release out of vNN branches
+    "^refs/heads/master$",
+    "^refs/heads/v\\d+(?:\\.\\d+)?$"
   ]
-}
+}