upgrade deps, update to go 1.18

[srabraham]

go 1.18 is the most recent supported version of Go, so it seems reasonable to upgrade to that. This upgrade is needed to pull in the latest version of smartystreets/assertions, which I want in here for this fix of mine: https://github.com/smartystreets/assertions/commit/a83f75f344d7f8c0681e5c699c5f747cd41cd93f

This also replaces all "interface{}" with "any", since go 1.18 added that. That was already done in the assertions repo the other day.

Note that this command passes: go test -timeout=1s -race -cover -short -count=1 ./...

but the integration test file fails. That failure is already in the repo at HEAD though.

This is a partial fix to https://github.com/smartystreets/goconvey/issues/665, since it pulls in the aforementioned assertions fix. See https://github.com/smartystreets/assertions/issues/50

[srabraham]

FYI @riannucci or others

[riannucci]

lgtm will pull and tag when I'm at computer

[srabraham]

bump @riannucci 😄

[riannucci]

(sorry for the delay!)

[srabraham]

Thanks, Robbie!