* Update to latest x/tools (2020/01/19).
Fixes#893
* Initialize vet analyzers as unexportd global vars.
Fixes#915
* Support testing Go 1.14beta1.
* ci: reset go.mod and go.sum before generated diff check
* Update to latest x/tools (2020/02/04)
Co-authored-by: Aleksandr Razumov <ar@gortc.io>
1. Support unparam linter and fix found issues
2. Replace forked mvdan.cc/lint and mvdan.cc/interfacer with the
upstream ones
3. Minimize forked megacheck: move the most of it's code to this repo
4. Use golang.org/x/tools/go/ssa import path instead of custom fork
paths
5. In golang.org/x/tools/go/{ssa,callgraph} use changed code from
honnef.co/go/tools
6. Add megacheck.check-unexported option: it found some issues in
the repo, fixed them all
