minor fixes
minor fixes

Fixed some minor issues found by Acrolinx software ;)
clojureD-conference/clojureD-conference.github.io,doctronic/clojureD-conference.github.io,clojureD-conference/clojureD-conference.github.io,doctronic/clojureD-conference.github.io,clojureD-conference/clojureD-conference.github.io,doctronic/clojureD-conference.github.io,doctronic/clojureD-conference.github.io,clojureD-conference/clojureD-conference.github.io