go.mod, vendor: update (#3358)

* go.mod, vendor: remove unnecessary dependencies

Commands:
1. go mod tidy
2. go mod vendor

* go.mod, vendor: update cloud.google.com/go

Commands:
1. go get -u cloud.google.com/go
2. go mod tidy
3. go mod vendor

* go.mod, vendor: update cloud.google.com/*

Commands:
1. go get -u cloud.google.com/storage cloud.google.com/logging
2. go mod tidy
3. go mod vendor

* go.mod, .golangci.yml, vendor: update *lint*

Commands:
1. go get -u golang.org/x/tools github.com/golangci/golangci-lint@v1.47.0
2. go mod tidy
3. go mod vendor
4. edit .golangci.yml to suppress new errors (resolved in the same PR later)

* all: fix lint errors

hash.go: copy() recommended by gosimple
parse.go: ent is never nil
verifier.go: signal.Notify() with unbuffered channel is bad. Have no idea why.

* .golangci.yml: adjust godot rules

check-all is deprecated, but still work
if you're hesitating too - I'll remove this commit

1 files changed, 59 insertions, 0 deletions

diff --git a/vendor/github.com/julz/importas/README.md b/vendor/github.com/julz/importas/README.md
new file mode 100644
index 000000000..1ea7b4fb2
--- /dev/null
+++ b/vendor/github.com/julz/importas/README.md
@@ -0,0 +1,59 @@
+A linter to enforce importing certain packages consistently.
+
+## What is this for?
+
+Ideally, go imports should avoid aliasing. Sometimes though, especially with
+Kubernetes API code, it becomes unavoidable, because many packages are imported
+as e.g. "[package]/v1alpha1" and you end up with lots of collisions if you use
+"v1alpha1". 
+
+This linter lets you enforce that whenever (for example)
+"pkg/apis/serving/v1alpha1" is aliased, it is aliased as "servingv1alpha1".
+
+## Usage
+
+~~~~
+importas \
+  -alias knative.dev/serving/pkg/apis/autoscaling/v1alpha1:autoscalingv1alpha1 \
+  -alias knative.dev/serving/pkg/apis/serving/v1:servingv1 \
+  ./...
+~~~~
+
+### `-no-unaliased` option
+
+By default, importas allows non-aliased imports, even when the package is specified by `-alias` flag.
+With `-no-unaliased` option, importas does not allow this.
+
+~~~~
+importas -no-unaliased \
+  -alias knative.dev/serving/pkg/apis/autoscaling/v1alpha1:autoscalingv1alpha1 \
+  -alias knative.dev/serving/pkg/apis/serving/v1:servingv1 \
+  ./...
+~~~~
+
+### `-no-extra-aliases` option
+
+By default, importas allows aliases which are not specified by `-alias` flags.
+With `-no-extra-aliases` option, importas does not allow any unspecified aliases.
+
+~~~~
+importas -no-extra-aliases \
+  -alias knative.dev/serving/pkg/apis/autoscaling/v1alpha1:autoscalingv1alpha1 \
+  -alias knative.dev/serving/pkg/apis/serving/v1:servingv1 \
+  ./...
+~~~~
+
+### Use regular expression
+
+You can specify the package path by regular expression, and alias by regular expression replacement syntax like following snippet.
+
+~~~~
+importas -alias 'knative.dev/serving/pkg/apis/(\w+)/(v[\w\d]+):$1$2'
+~~~~
+
+`$1` represents the text of the first submatch. See [detail](https://golang.org/pkg/regexp/#Regexp.Expand).
+
+So it will enforce that
+
+"knative.dev/serving/pkg/apis/autoscaling/v1alpha1" is aliased by "autoscalingv1alpha1", and
+"knative.dev/serving/pkg/apis/serving/v1" is aliased by "servingv1"