Add hoplon and javelin as a plugin (#73)

* Hoplon and Javelin plugins

* Only Hoplon plugin

* Bump promesa

* Update sci context access/update

* Bump sci

plugins/javelin/src/scittle_plugin.edn

@@ -0,0 +1,8 @@
+[{:name scittle/javelin
+  :namespaces [javelin.core]
+  :js "./scittle.javelin.js"
+  :shadow-config
+  {:modules
+   {:scittle.javelin {:init-fn scittle.javelin/init
+                      :depends-on #{:scittle}
+                      :entries [javelin.core]}}}}]