Update downcast dependency

It wasn't able to compile with latest Rust 1.33

diff --git a/Cargo.toml b/Cargo.toml
index ed38a9a3507a30750713ab887f2e356e454cc61d..343e43515c990347516e18b5ba8a895471f8ddba 100644 (file)
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -11,7 +11,7 @@ default = ["readline_rs_compat"]
 
 [dependencies]
 cfg-if = "0.1.7"
-downcast = "0.9.1"
+downcast = "0.10.0"
 num = "0.2"
 ordered-float = "0.5.0"
 prolog_parser = "0.8.3"
@@ -19,4 +19,4 @@ readline_rs_compat = { version = "0.1.7", optional = true }
 ref_thread_local = "0.0.0"
 
 [dependencies.termion]
-version = "1.4.0"
\ No newline at end of file
+version = "1.4.0"