Refactor to `configService` to read & write `Config`

`configService` can save and load `Config` using a strategy of `configEncoder` and `configDecoder`. This pave the path for swapping out `tomlConfigEncoder` and `tomlConfigDecoder` with `yamlConfigEncoder` and `yamlConfigDecoder`.

`Configs` also has been renamed to `Config`.
Merge pull request #620 from github/gh_yaml

Refactor to `configService` to read & write `Config`
Revert cukes to test yaml config
Add `yamlConfigEncoder` and `yamlConfigDecoder`
Add `go-yaml`
Load yaml config
Turns out Host is an array for the YAML format
Remove toml related code in cukes
Merge branch 'gh_yaml_fix' into gh
Provide option to build `hub` without autoupdate
Merge branch 'no_update' into gh
Merge pull request #601 from github/no-curl

gh: Move away from using curl for patches and to GitHub API
Clean up package script