This commit was created by manually removing github.com/ugorji/go/codec from
the go.mod (which now does not exist - see https://github.com/ugorji/go/issues/299)
and running `go mod tidy`.
Closes#658
In Go 1.11.4 a bug was fixed related to checksum calculation.
As a result, some packages might end up with a different checksum
from this version. The solution is upgrading, cleaning the mod cache
and recalculating the go.sum file.
See https://github.com/golang/go/issues/27093