Update Project.toml

Author: MasonProtter

Project.toml

@@ -24,7 +24,7 @@ AssetRegistry = "0.1.0"
 FunctionalCollections = "0.5.0"
 JSExpr = "0.5"
 JSON = "0.18, 0.19, 0.20, 0.21"
-Observables = "0.4, 0.5"
+Observables = "0.5"
 Requires = "0.4.4, 0.5, 1.0.0"
 WebSockets = "1.5.0"
 Widgets = "0.6.2"