Make repository self-contained

[liamsi]

This tendermint fork was renamed and lives under a different organization. Some trivial changes are necessary to make this repository useable (and not still use the orig tendermint

• [x] replace paths s.t. this uses github.com/lazyledger/lazyledger-core/* and deal with go.mod
• [x] update circle-ci or better: switch to github actions
• [x] delete all attached releases: https://github.com/LazyLedger/lazyledger-core/releases

@marbar3778 has a branch with an (almost) working version of CI using github actions (see https://github.com/marbar3778/tendermint/pull/5/files). We should help fixing this as we are currently not using any CI.

Current configuration is using circleci, here: https://github.com/LazyLedger/lazyledger-core/blob/da745371227f54aa90c609845cd4cc2f36a152f1/.circleci/config.yml#L1-L450

[liamsi]

deleted all existing releases (via little bash script), we can switch to github actions later, step by step