Upgrade to substrate 2.0.0 (#173)

* Upgrade to substrate 2.0.0

* WIP implement Subcommand manually (see https://github.com/paritytech/substrate/pull/6894#issuecomment-676060197)

* Add pallet-staking/std to the std feature

* Sort out the subcommand impl

* Sort out the module index (ty @ascjones)
Sort out the RefCount type (ty @dvc94ch)
Random tweaks to make test-node more similar to the vanilla node-template

* obey the fmt

* cleanup

* more cleanup

src/frame/contracts.rs

@@ -116,6 +116,7 @@ pub struct InstantiatedEvent<T: Contracts> {
 }
 
 #[cfg(test)]
+#[cfg(feature = "integration-tests")]
 mod tests {
     use sp_keyring::AccountKeyring;