Put cumulus-parachain-upgrade into the test parachain (#98)

This ensures that the crate compiles for `no_std`. Besides this, there
are some fixes to the crate code itself.

cumulus/test/parachain/runtime/Cargo.toml

@@ -33,6 +33,7 @@ pallet-transaction-payment = { git = "https://github.com/paritytech/substrate",
 
 # Cumulus dependencies
 cumulus-runtime = { path = "../../../runtime", default-features = false }
+cumulus-parachain-upgrade = { path = "../../../parachain-upgrade", default-features = false }
 
 [build-dependencies]
 wasm-builder-runner = { package = "substrate-wasm-builder-runner", version = "1.0.3" }
@@ -63,4 +64,5 @@ std = [
 	'pallet-sudo/std',
 	'pallet-transaction-payment/std',
 	'cumulus-runtime/std',
+	'cumulus-parachain-upgrade/std',
 ]