Backport test case for 1.5

Go 1.5 does not have a rand.Read function so need to adjust test
definitions accordingly.

Author: gcmurphy

rules/rand.go

@@ -22,21 +22,23 @@ import (
 
 type WeakRand struct {
 	gas.MetaData
-	funcName    string
+	funcNames   []string
 	packagePath string
 }
 
 func (w *WeakRand) Match(n ast.Node, c *gas.Context) (*gas.Issue, error) {
-	if _, matched := gas.MatchCallByPackage(n, c, w.packagePath, w.funcName); matched {
-		return gas.NewIssue(c, n, w.What, w.Severity, w.Confidence), nil
+	for _, funcName := range w.funcNames {
+		if _, matched := gas.MatchCallByPackage(n, c, w.packagePath, funcName); matched {
+			return gas.NewIssue(c, n, w.What, w.Severity, w.Confidence), nil
+		}
 	}
 
 	return nil, nil
 }
 
 func NewWeakRandCheck(conf map[string]interface{}) (gas.Rule, []ast.Node) {
 	return &WeakRand{
-		funcName:    "Read",
+		funcNames:   []string{"Read", "Int"},
 		packagePath: "math/rand",
 		MetaData: gas.MetaData{
 			Severity:   gas.High,

rules/rand_test.go

@@ -51,7 +51,7 @@ func TestRandBad(t *testing.T) {
 		import "math/rand"
 
 		func main() {
-			bad, _ := rand.Read(nil)
+			bad := rand.Int()
 			println(bad)
 
 		}`, analyzer)
@@ -77,7 +77,7 @@ func TestRandRenamed(t *testing.T) {
 		func main() {
 			good, _ := rand.Read(nil)
 			println(good)
-			i := mrand.Int()
+			i := mrand.Int31()
 			println(i)
 		}`, analyzer)