tests: use standard library testing.TB

Glint pulled in an updated version of mitchellh/go-testing-interface
which broke some existing tests because the update added a Parallel()
method to testing.T. This switches to the standard library testing.TB
which doesn't have a Parallel() method.

command/agent/http_test.go

@@ -34,7 +34,7 @@ import (
 
 // makeHTTPServer returns a test server whose logs will be written to
 // the passed writer. If the writer is nil, the logs are written to stderr.
-func makeHTTPServer(t testing.T, cb func(c *Config)) *TestAgent {
+func makeHTTPServer(t testing.TB, cb func(c *Config)) *TestAgent {
 	return NewTestAgent(t, t.Name(), cb)
 }
 

command/agent/testagent.go

@@ -10,10 +10,9 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
+	"testing"
 	"time"
 
-	testing "github.com/mitchellh/go-testing-interface"
-
 	metrics "github.com/armon/go-metrics"
 	"github.com/hashicorp/go-hclog"
 	"github.com/hashicorp/nomad/api"
@@ -39,7 +38,7 @@ var TempDir = os.TempDir()
 // is removed after shutdown.
 type TestAgent struct {
 	// T is the testing object
-	T testing.T
+	T testing.TB
 
 	// Name is an optional name of the agent.
 	Name string
@@ -92,7 +91,7 @@ type TestAgent struct {
 // NewTestAgent returns a started agent with the given name and
 // configuration. The caller should call Shutdown() to stop the agent and
 // remove temporary directories.
-func NewTestAgent(t testing.T, name string, configCallback func(*Config)) *TestAgent {
+func NewTestAgent(t testing.TB, name string, configCallback func(*Config)) *TestAgent {
 	a := &TestAgent{
 		T:              t,
 		Name:           name,