Delete vendored code and update CI to Go 1.13 (#158)

As the Go community transitions to using the modules ecosystem,
we want to only support one way of managing dependencies.
So this change moves to only using Go modules for dependency management.

This means that our effective minimum Go version increases to Go 1.11.
To account for this, we also update:
  - the documentation
  - Makefile
  - CI scripts

1 files changed, 0 insertions, 32 deletions

diff --git a/vendor/github.com/pkg/errors/appveyor.yml b/vendor/github.com/pkg/errors/appveyor.yml
deleted file mode 100644
index a932ead..0000000
--- a/vendor/github.com/pkg/errors/appveyor.yml
+++ /dev/null
@@ -1,32 +0,0 @@
-version: build-{build}.{branch}
-
-clone_folder: C:\gopath\src\github.com\pkg\errors
-shallow_clone: true # for startup speed
-
-environment:
-  GOPATH: C:\gopath
-
-platform:
-  - x64
-
-# http://www.appveyor.com/docs/installed-software
-install:
-  # some helpful output for debugging builds
-  - go version
-  - go env
-  # pre-installed MinGW at C:\MinGW is 32bit only
-  # but MSYS2 at C:\msys64 has mingw64
-  - set PATH=C:\msys64\mingw64\bin;%PATH%
-  - gcc --version
-  - g++ --version
-
-build_script:
-  - go install -v ./...
-
-test_script:
-  - set PATH=C:\gopath\bin;%PATH%
-  - go test -v ./...
-
-#artifacts:
-#  - path: '%GOPATH%\bin\*.exe'
-deploy: off