Spawn test node process for integration tests (#252)

* Move tests to module in own file

* Add test-node-proc crate

* Move test node to main lib, fix compilation errors

* Fmt

* Attempted port scanning

* Use global static port to allocate open ports

* Register missing type sizes

* Fix port scanning and balances test

* Don't wait for blocks on insert_jey test

* Fmt

* Remove unused dependencies

* Download v3.0.0 rust binary

* Move substrate bin to home dir

* Add test instructions to README

* Figure out the $PATH

* Remove path echo

* Add check for missing substrate binary on the PATH

* @niklasad1 review: don't include client feature for tests

.github/workflows/rust.yml

@@ -23,6 +23,13 @@ jobs:
           components: rustfmt
           target: wasm32-unknown-unknown
 
+    - name: download-substrate
+      run: |
+          curl "https://releases.parity.io/substrate/x86_64-debian:stretch/v3.0.0/substrate/substrate" --output substrate --location
+          chmod +x ./substrate
+          mkdir -p ~/.local/bin
+          mv substrate ~/.local/bin
+
     - name: fmt
       run: cargo fmt --all -- --check