Add ci to repo

[aatifsyed]

current rust #[test]s are for docs etc, no e2e tests yet

[aatifsyed]

See also #25

[LesnyRumcajs]

@elmattic Could you please provide a description with tasks to do within this issue? I imagine we should start with a smallest CI possible, then iterate from there.

[elmattic]

The kind of tests we want to add to the CI are basically those covered by cargo test:

cargo test --manifest-path ./rust/Cargo.toml

[elmattic]

e2e tests would be the ones run by the test-suite tool and/or openrpc validate of a capture.

[LesnyRumcajs]

@ansermino @elmattic given #42 and #40, do we consider this issue closed?

[elmattic]

I think so.