support reagent :style hashmaps in hiccup forms

[retrogradeorbit]

$ bootleg -e '[:div {:style "color:red;"}]'
<div style="color:red;"></div>

$ bootleg -e '[:div {:style {:color "red"}}]'
Exception in thread "main" java.lang.ClassCastException: clojure.lang.PersistentArrayMap cannot be cast to java.lang.String
	at quoin.text$html_escape.invokeStatic(text.clj:12)
	at quoin.text$html_escape.invoke(text.clj:4)
	at hickory.utils$html_escape.invokeStatic(utils.cljc:27)
	at hickory.utils$html_escape.invoke(utils.cljc:25)
	at hickory.render$render_hiccup_attrs$iter__367__371$fn__372.invoke(render.cljc:82)
	at clojure.lang.LazySeq.sval(LazySeq.java:42)
	at clojure.lang.LazySeq.seq(LazySeq.java:51)
	at clojure.lang.RT.seq(RT.java:531)
	at clojure.core$seq__5387.invokeStatic(core.clj:137)
	at clojure.core$filter$fn__5878.invoke(core.clj:2809)
	at clojure.lang.LazySeq.sval(LazySeq.java:42)
	at clojure.lang.LazySeq.seq(LazySeq.java:58)
	at clojure.lang.RT.seq(RT.java:531)
	at clojure.core$seq__5387.invokeStatic(core.clj:137)
	at clojure.core$sort.invokeStatic(core.clj:3113)
	at clojure.core$sort.invokeStatic(core.clj:3102)
	at clojure.core$sort.invoke(core.clj:3102)
	at hickory.render$render_hiccup_attrs.invokeStatic(render.cljc:85)
	at hickory.render$render_hiccup_attrs.invoke(render.cljc:69)
	at hickory.render$render_hiccup_element.invokeStatic(render.cljc:102)
	at hickory.render$render_hiccup_element.invoke(render.cljc:93)
	at hickory.render$render_hiccup_form.invokeStatic(render.cljc:113)
	at hickory.render$render_hiccup_form.invoke(render.cljc:106)
	at hickory.render$hiccup_to_html$fn__394.invoke(render.cljc:141)
...