Modernize build: bump Go version, golangci-lint, fix lint errors...

Also provide go.mod/go.sum, build with modules enabled.

.golangci.yml

@@ -0,0 +1,16 @@
+linters:
+  enable:
+    - gofmt
+    - gosec
+    - unconvert
+    - misspell
+    - goimports
+    - megacheck
+    - staticcheck
+    - unused
+    - deadcode
+    - typecheck
+    - ineffassign
+    - golint
+    - stylecheck
+    - unparam

.travis.yml

@@ -1,13 +1,19 @@
-dist: trusty
+dist: xenial
 sudo: false
 
 language: go
 
 go:
-  - 1.9.x
-  - 1.10.x
+  - 1.11.x
+  - 1.12.x
   - master
 
+env:
+  - GO111MODULE=on
+
+before_install:
+  - curl -sfL https://install.goreleaser.com/github.com/golangci/golangci-lint.sh | sh -s -- -b $(go env GOPATH)/bin v1.16.0
+
 matrix:
     allow_failures:
         - go: master

Makefile

@@ -1,18 +1,12 @@
 all: test check bench
 
-deps:
-	go get -v -d -t ./...
-	go get -v github.com/alecthomas/gometalinter
-	gometalinter --install
-
-test: deps
+test:
 	go test -race -v -coverprofile=coverage.txt -covermode=atomic
 
-bench: deps
+bench:
 	go test -v -run ^Test$$ -bench=. ./... -gocheck.b
 
 check:
-	go test -i
-	gometalinter --vendored-linters --deadline=30s --cyclo-over=16 ./...
+	golangci-lint run
 
-.PHONY: deps test bench check
+.PHONY: test bench check

dbscan.go

@@ -37,7 +37,7 @@ type EpsFunction func(pt Point) float64
 // DBScan clusters incoming points into clusters with params (eps, minPoints)
 //
 // eps is clustering radius in km
-// minPoints in minumum number of points in eps-neighbourhood (density)
+// minPoints in minimum number of points in eps-neighbourhood (density)
 func DBScan(points PointList, eps float64, minPoints int) (clusters []Cluster, noise []int) {
 	visited := make([]bool, len(points))
 	members := make([]bool, len(points))

distance.go

@@ -5,7 +5,7 @@ import (
 )
 
 const (
-	// DegreeRad is coefficent to translate from degrees to radians
+	// DegreeRad is coefficient to translate from degrees to radians
 	DegreeRad = math.Pi / 180.0
 	// EarthR is earth radius in km
 	EarthR = 6371.0

distance_test.go

@@ -1,8 +1,9 @@
 package cluster
 
 import (
-	. "gopkg.in/check.v1"
 	"math"
+
+	. "gopkg.in/check.v1"
 )
 
 type DistanceSuite struct {

go.mod

@@ -0,0 +1,9 @@
+module github.com/smira/go-point-clustering
+
+go 1.12
+
+require (
+	github.com/kr/pretty v0.1.0 // indirect
+	github.com/willf/bitset v1.1.10
+	gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127
+)

go.sum

@@ -0,0 +1,9 @@
+github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
+github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
+github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
+github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
+github.com/willf/bitset v1.1.10 h1:NotGKqX0KwQ72NUzqrjZq5ipPNDQex9lo3WpaS8L2sc=
+github.com/willf/bitset v1.1.10/go.mod h1:RjeCKbqT1RxIR/KWY6phxZiaY1IyutSBfGjNPySAYV4=
+gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 h1:qIbj1fsPNlZgppZ+VLlY7N33q108Sa+fhmuc+sWQYwY=
+gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

point_test.go

@@ -1,8 +1,9 @@
 package cluster
 
 import (
-	. "gopkg.in/check.v1"
 	"testing"
+
+	. "gopkg.in/check.v1"
 )
 
 // Launch gocheck tests