[vpython] Incorporate interpreter path/hash.

vpython/python/python_test.go

Index: vpython/python/python_test.go
diff --git a/vpython/python/python_test.go b/vpython/python/python_test.go
index 4161ad10f695d39bf7ca287feb283f9e1a9bf699..695010914496c8b89924787038ed8b9d65513890 100644
--- a/vpython/python/python_test.go
+++ b/vpython/python/python_test.go
@@ -123,6 +123,14 @@ func TestInterpreter(t *testing.T) {
 			Python: self,
 		}
 
+		Convey(`Testing hash`, func() {
+			hash, err := i.Hash()
+			So(err, ShouldBeNil)
+			So(hash, ShouldNotEqual, "")
+
+			t.Logf("Calculated interpreter hash: %s", hash)
+		})
+
 		Convey(`Testing IsolatedCommand`, func() {
 			cmd := i.IsolatedCommand(c, "foo", "bar")
 			So(cmd.Args, ShouldResemble, []string{self, "-B", "-E", "-s", "foo", "bar"})