* use runtime image
* no need to compile with `make 2k`
* use new go-sdk /2 (#36)
* use new go-sdk
* use custom runtime image (#38)
* improve runtime image
* remove redundant runners
* enable go build cache
* remove replace lotus directive
* add git clone for lotus as part of manifest.toml
* use base build image
* compile `lotus-testground` on `current master` from Lotus (#41)
* automated scripts to build/push base build and runtime images
* go mod tidy and new version of lotus in manifest
* fix types
* fix storage miner (#42)
* fix storage miner
* update runtime image to ubuntu
