[CI] Add more checks (#43)

vendor/github.com/jgautheron/goconst/README.md

@@ -0,0 +1,49 @@
+# goconst
+
+Find repeated strings that could be replaced by a constant.
+
+### Motivation
+
+There are obvious benefits to using constants instead of repeating strings, mostly to ease maintenance. Cannot argue against changing a single constant versus many strings.
+
+While this could be considered a beginner mistake, across time, multiple packages and large codebases, some repetition could have slipped in.
+
+### Get Started
+
+    $ go get github.com/jgautheron/goconst/cmd/goconst
+    $ goconst ./...
+
+### Usage
+
+```
+Usage:
+
+  goconst ARGS <directory>
+
+Flags:
+
+  -ignore            exclude files matching the given regular expression
+  -ignore-tests      exclude tests from the search (default: true)
+  -min-occurrences   report from how many occurrences (default: 2)
+  -min-length        only report strings with the minimum given length (default: 3)
+  -match-constant    look for existing constants matching the values
+  -numbers           search also for duplicated numbers
+  -min          	   minimum value, only works with -numbers
+  -max          	   maximum value, only works with -numbers
+  -output            output formatting (text or json)
+
+Examples:
+
+  goconst ./...
+  goconst -ignore "yacc|\.pb\." $GOPATH/src/github.com/cockroachdb/cockroach/...
+  goconst -min-occurrences 3 -output json $GOPATH/src/github.com/cockroachdb/cockroach
+  goconst -numbers -min 60 -max 512 .
+```
+
+### Other static analysis tools
+
+- [gogetimports](https://github.com/jgautheron/gogetimports): Get a JSON-formatted list of imports.
+- [usedexports](https://github.com/jgautheron/usedexports): Find exported variables that could be unexported.
+
+### License
+MIT