Update exit-future and make sc-cli compile on wasm (#4289)

* updated exit-future (github repo)

* Switch to broadcast crate

* Migrate client/cli

* Switch exit-future to modernize branch

* Small changes

* Switch to cargo version and fix fg tests

* Revert "Small changes"

This reverts commit a488106805d220cb4aee9e46a71481424c6d87d5.

substrate/client/cli/Cargo.toml

@@ -16,9 +16,8 @@ time = "0.1.42"
 ansi_term = "0.12.1"
 lazy_static = "1.4.0"
 app_dirs = "1.2.1"
-tokio = "0.1.22"
+tokio = "0.2.1"
 futures = { version = "0.3.1", features = ["compat"] }
-futures01 = "0.1.29"
 fdlimit = "0.1.1"
 serde_json = "1.0.41"
 panic-handler = { package = "sp-panic-handler", path = "../../primitives/panic-handler" }
@@ -33,9 +32,11 @@ sc-telemetry = { path = "../telemetry" }
 keyring = { package = "sp-keyring", path = "../../primitives/keyring" }
 names = "0.11.0"
 structopt = "0.3.3"
-rpassword = "4.0.1"
 sc-tracing = { package = "sc-tracing", path = "../tracing" }
 
+[target.'cfg(not(target_os = "unknown"))'.dependencies]
+rpassword = "4.0.1"
+
 [dev-dependencies]
 tempfile = "3.1.0"