minor: pin to async-std 1.5.x (#187)

saghm · web-flow · commit dfd951fa3b44 · 2020-05-28T13:08:49.000-04:00
diff --git a/Cargo.toml b/Cargo.toml
@@ -48,7 +48,7 @@ webpki = "0.21.0"
 webpki-roots = "0.18.0"
 
 [dependencies.async-std]
-version = "1.5.0"
+version = "~1.5.0"
 optional = true
 
 [dependencies.pbkdf2]
