Merge pull request #167 from cfm/one-crab-to-rule-them-all

proof: extract a single pattern to start

Author: cfm

.gitignore

@@ -27,3 +27,8 @@ node_modules/
 securedrop-protocol/pkg/*
 securedrop-protocol/.selenium-cache
 securedrop-protocol/out
+
+# hax/F*
+.fstar-cache/
+.depend
+hax.fst.config.json