Remove dependency on gobuffalo/envy

Closes #45

Credit to @dcelasun for the basis of the code

box.go

@@ -12,7 +12,6 @@ import (
 
 	"compress/gzip"
 
-	"github.com/gobuffalo/envy"
 	"github.com/pkg/errors"
 )
 
@@ -34,7 +33,7 @@ func NewBox(path string) Box {
 	cov := filepath.Join("_test", "_obj_test")
 	cd = strings.Replace(cd, string(filepath.Separator)+cov, "", 1)
 	if !filepath.IsAbs(cd) && cd != "" {
-		cd = filepath.Join(envy.GoPath(), "src", cd)
+		cd = filepath.Join(GoPath(), "src", cd)
 	}
 
 	return Box{

builder/builder_test.go

@@ -9,7 +9,7 @@ import (
 	"path/filepath"
 	"testing"
 
-	"github.com/gobuffalo/envy"
+	"github.com/gobuffalo/packr"
 	"github.com/stretchr/testify/require"
 )
 
@@ -91,7 +91,7 @@ func Test_Binary_Builds(t *testing.T) {
 	r.NoError(err)
 
 	os.Chdir(root)
-	cmd := exec.Command(envy.Get("GO_BIN", "go"), "build", "-v", "-o", "bin/example")
+	cmd := exec.Command(packr.GoBin(), "build", "-v", "-o", "bin/example")
 	err = cmd.Run()
 	r.NoError(err)
 

env.go

@@ -0,0 +1,27 @@
+package packr
+
+import (
+	"go/build"
+	"os"
+	"strings"
+)
+
+// GoPath returns the current GOPATH env var
+// or if it's missing, the default.
+func GoPath() string {
+	go_path := strings.Split(os.Getenv("GOPATH"), string(os.PathListSeparator))
+	if len(go_path) == 0 || go_path[0] == "" {
+		return build.Default.GOPATH
+	}
+	return go_path[0]
+}
+
+// GoBin returns the current GO_BIN env var
+// or if it's missing, a default of "go"
+func GoBin() string {
+	go_bin := os.Getenv("GO_BIN")
+	if go_bin == "" {
+		return "go"
+	}
+	return go_bin
+}

packr/cmd/build.go

@@ -5,7 +5,7 @@ import (
 	"os"
 	"os/exec"
 
-	"github.com/gobuffalo/envy"
+	"github.com/gobuffalo/packr"
 	"github.com/gobuffalo/packr/builder"
 	"github.com/pkg/errors"
 	"github.com/spf13/cobra"
@@ -26,7 +26,7 @@ var buildCmd = &cobra.Command{
 
 		cargs := []string{"build"}
 		cargs = append(cargs, args...)
-		cp := exec.Command(envy.Get("GO_BIN", "go"), cargs...)
+		cp := exec.Command(packr.GoBin(), cargs...)
 		cp.Stderr = os.Stderr
 		cp.Stdin = os.Stdin
 		cp.Stdout = os.Stdout

packr/cmd/install.go

@@ -7,7 +7,7 @@ import (
 	"path/filepath"
 	"strings"
 
-	"github.com/gobuffalo/envy"
+	"github.com/gobuffalo/packr"
 	"github.com/gobuffalo/packr/builder"
 	"github.com/pkg/errors"
 	"github.com/spf13/cobra"
@@ -22,7 +22,7 @@ var installCmd = &cobra.Command{
 		if len(args) > 0 {
 			input = args[len(args)-1]
 			if !strings.HasPrefix(input, ".") {
-				input = filepath.Join(envy.GoPath(), "src", input)
+				input = filepath.Join(packr.GoPath(), "src", input)
 				if _, err := os.Stat(input); err != nil {
 					return errors.WithStack(err)
 				}
@@ -37,7 +37,7 @@ var installCmd = &cobra.Command{
 
 		cargs := []string{"install"}
 		cargs = append(cargs, args...)
-		cp := exec.Command(envy.Get("GO_BIN", "go"), cargs...)
+		cp := exec.Command(packr.GoBin(), cargs...)
 		cp.Stderr = os.Stderr
 		cp.Stdin = os.Stdin
 		cp.Stdout = os.Stdout