Coerce balance to float to avoid crash

Token balances are expected to have float values in services.clj, but
can end up with integer value, so we need to coerce.

src/clj/commiteth/eth/multisig_wallet.clj

@@ -141,7 +141,7 @@
                (Math/pow 10 token-base)
                token-base)]
     (assert (> base 0))
-    (/ value base)))
+    (float (/ value base))))
 
 
 (defn token-balance-in-bounty