Switch Rosetta integration tests back to use mainstream rosetta-cli.

[Sventimir]

At the moment our rosetta-cli test contain stake delegations, which are not yet handled by mainteream rosetta-cli. To have them supported, we made changes to rosetta-sdk-go and until they're merged, we have to use our fork of rosetta-sdk-go in our CI. Once our contribution is merged and released, we need to switch our CI to use mainstream rosetta-cli for testing.

• The pull request we're waiting for is: #464
• When it's merged we can switch to pulling master branch of rosetta-sdk-go in our tests
• When these changes are released, we can pull main-line rosetta-cli binary rather than compile it from sources.

[kantp]

I got feedback from Coinbase on the PR:
There are two places where Mina is mentioned in the code:

• https://github.com/coinbase/rosetta-sdk-go/pull/464/files#diff-0f3ab1719ea32fedb129223380d6f326ceff2708d23d99a5af7f60f337c746e5R161
• https://github.com/coinbase/rosetta-sdk-go/pull/464/files#diff-0f3ab1719ea32fedb129223380d6f326ceff2708d23d99a5af7f60f337c746e5R24

We'd need to remove those in order to get the PR merged upstream.