Add sleet

[daisy1754]

• github.com repo: https://github.com/BoltApp/sleet
• pkg.go.dev: https://pkg.go.dev/github.com/BoltApp/sleet?tab=doc
• goreportcard.com: https://goreportcard.com/report/github.com/BoltApp/sleet
• coverage service link: https://codecov.io/gh/BoltApp/sleet

Make sure that you've checked the boxes below before you submit PR:

• I have added my package in alphabetical order.
• I have an appropriate description with correct grammar.
• I know that this package was not listed before.
• I have added pkg.go.dev link to the repo and to my pull request.
• I have added coverage service link to the repo and to my pull request.
• I have added goreportcard link to the repo and to my pull request.
• I have read Contribution guidelines, maintainers note and Quality standard.

[avelino]

Thank you for contributing with awesome-go, we will revise your contribution as soon as possible.

Automation body links content check:

• godoc.org or pkg.go.dev: True
• goreportcard.com: True
• coverage: True

your project is about to be approved, it's under revision, it may take a few days

[avelino]

review:

• coverage is 70.95%

[...] then coverage should be >= 80% for non-data-related packages and >=90% for data related packages [...]

• golint https://goreportcard.com/report/github.com/BoltApp/sleet#golint

read more: https://github.com/avelino/awesome-go/blob/master/CONTRIBUTING.md#quality-standards

[daisy1754]

working on adding test. For golint, it seems guideline isn't super explicit about requirement. Is 100% golint requirement? I want to avoid having redundunt comment like below

// TransactionType transaction type
TransactionType

[daisy1754]

FWIW author of lint suggests ignoring lint when it's not relevant golang/lint#186 (comment)

[avelino]

We don't ask for 100% lint, we recommend that you have all lint items corrected to keep the quality of your package to a minimum.

In my view if it is possible to correct, why not correct?

[daisy1754]

IMO in some cases (please refer to my example above), "fixing" lint would actually do more harm than benefit. When variable name is self explanatory I prefer not to have comment.

Anyways we're working on increasing coverage. I'll update here once it's ready

[daisy1754]

@avelino coverage is now 80%+ https://codecov.io/gh/BoltApp/sleet
I went thorough and fixed lint mostly, but didn't add some redundunt comments so score is not 100 (but I believe this is better than adding redundunt comment just for sake of lint score).

Please kindly review again.