Merge pull request #15 from jbowes/go-116

update go mod for 1.16

Merge pull request #10 from jbowes/use-github-actions

Use github actions instead of travis

Merge pull request #8 from jelmersnoeck/add-vice-for-error

Implement ForError function

Merge pull request #7 from jelmersnoeck/precondition-vice

Add Precondition error behaviour

Merge pull request #5 from jelmersnoeck/add-no-vice-checks

Add NoVice checks.

Merge pull request #4 from jelmersnoeck/add-canceled

add canceled type

Merge pull request #3 from jelmersnoeck/add-internal-type

add internal error type

Merge pull request #2 from tooolbox/master

Make Wrap() and Seal() on nil return nil

Add examples and usage