Handle invalid keywords correctly when exporting workspaces to disk #581
Description
When a workspace is exported to disk using poly ws out:myws.edn, certain keys may contain invalid values, causing the resulting file to be unreadable, for example this key, which is read by the json-reader as a :@poly/web-app keyword. Clojure allows these keywords to be created from a string even though they are illegal.
The solution is to wrap these keywords with "" to make strings of them, e.g. ":@poly/web-app".