to url and to toml (#396)

* MathEval Variance and Stddev

* Fix tests and linting

* Typo

* Deal with streams when they are not tables

* ToUrl and ToToml

* Linting

crates/nu-command/src/default_context.rs

@@ -152,6 +152,8 @@ pub fn create_default_context() -> EngineState {
             Table,
             To,
             ToJson,
+            ToUrl,
+            ToToml,
             Touch,
             Use,
             Update,