concat on Flowable throws exception

[tsachev]

Currently it is not possible to use rx/concat with Flowable

java.lang.IllegalArgumentException: No matching method found: concat
 at clojure.lang.Reflector.invokeMatchingMethod (Reflector.java:80)
    clojure.lang.Reflector.invokeStaticMethod (Reflector.java:207)
    beicon.core$concat$fn__1040.invoke (core.cljc:857)
    clojure.core.protocols$fn__6755.invokeStatic (protocols.clj:167)
    clojure.core.protocols/fn (protocols.clj:124)
    clojure.core.protocols$fn__6710$G__6705__6719.invoke (protocols.clj:19)
    clojure.core.protocols$seq_reduce.invokeStatic (protocols.clj:27)
    clojure.core.protocols$fn__6738.invokeStatic (protocols.clj:75)
    clojure.core.protocols/fn (protocols.clj:75)
    clojure.core.protocols$fn__6684$G__6679__6697.invoke (protocols.clj:13)
    clojure.core$reduce.invokeStatic (core.clj:6541)
    clojure.core$reduce.invoke (core.clj:6527)
    beicon.core$concat.invokeStatic (core.cljc:854)
    beicon.core$concat.doInvoke (core.cljc:846)
    clojure.lang.RestFn.invoke (RestFn.java:421)

in the jvm version it seems that the concat implementation is assuming that arguments are always Observable.

Here is a simple test case to reproduce

#?(:clj
   (t/deftest flowable-concat
     (let [s1 (flowable-from-coll [1 2 3])
           s2 (flowable-from-coll [4 5 6])
           cs (s/concat s1 s2)]
       (drain! cs #(t/is (= % [1 2 3 4 5 6]))))))

[niwinz]

Thanks!