Replace safe-get used in letk
Fix boolean -> s/Bool schemas
Fix keywordize-map
Use type instead of class
Add repl-related gitignores
Fix sentinel in update-in-when

ClojureScript Keywords don't work for identical? Define a keyword once so that
identical works?

Note: ClojureScript has keyword-identical?, but this is marginally more
efficient (not creating 2 Keyword objects per call)
Fix merge-on-with-test
Add millis for CLJS
Use format from schema-utils
Use non-snapshot version of schema 0.2.2