Update to rules_go and buildtools

[drigz]

This fixes the build with Bazel 0.27. Fixes #955.

[johanbrandhorst]

Fixes #955 presumably

[drigz]

I noticed that the WORKSPACE contains references to the old Gopkg.toml. Since the switch to vgo, the dependencies versions used in the Golang and Bazel builds are different. We could consider using:

bazel run //:gazelle -- update-repos -from_file=go.mod

to autogenerate the WORKSPACE to match go.mod, but let's focus on the current problem for now.

[johanbrandhorst]

@drigz I would like that please. Could you open a separate PR with that change?

[drigz]

Fixes #955 presumably

Not yet :/

[codecov-io]

Codecov Report

Merging #956 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #956   +/-   ##
=======================================
  Coverage   53.23%   53.23%           
=======================================
  Files          40       40           
  Lines        3999     3999           
=======================================
  Hits         2129     2129           
  Misses       1672     1672           
  Partials      198      198

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[drigz]

@johanbrandhorst PTAL, CI is green now.

[johanbrandhorst]

I noticed that the WORKSPACE contains references to the old Gopkg.toml. Since the switch to vgo, the dependencies versions used in the Golang and Bazel builds are different. We could consider using:

bazel run //:gazelle -- update-repos -from_file=go.mod

to autogenerate the WORKSPACE to match go.mod, but let's focus on the current problem for now.

This would still be nice if you've got spare cycles!