Re-enable vpython/venv's TestVirtualEnv.

vpython/venv/venv_test.go

 // Copyright 2017 The LUCI Authors. All rights reserved.
 // Use of this source code is governed under the Apache License, Version 2.0
 // that can be found in the LICENSE file.
 
 package venv
 
 import (
         "encoding/json"
         "fmt"
         "io/ioutil"
@@ skipping 161 matching lines @@
                         So(v.Delete(c), ShouldBeNil)
                         return nil
                 })
                 So(err, ShouldBeNil)
         }))
 }
 
 func TestVirtualEnv(t *testing.T) {
         t.Parallel()
 
-        // TODO(dnj): Identify flake and fix.
-        t.Skip("Test is currently flaky, will re-enable once resolved.")
-
         for _, tc := range []struct {
                 name string
                 ri   *resolvedInterpreter
         }{
                 {"python27", python27},
                 {"python3", python3},
         } {
                 tc := tc
 
                 t.Run(fmt.Sprintf(`Testing Virtualenv for: %s`, tc.name), func(t *testing.T) {
                         testVirtualEnvWith(t, tc.ri)
                 })
         }
 }
 
 func loadJSON(path string, dst interface{}) error {
         content, err := ioutil.ReadFile(path)
         if err != nil {
                 return errors.Annotate(err).Reason("failed to open file").Err()
         }
         if err := json.Unmarshal(content, dst); err != nil {
                 return errors.Annotate(err).Reason("failed to unmarshal JSON").Err()
         }
         return nil
 }