Add a test for BeforeStep in multisteps

This demonstrates the bug reported in #486

features/multistep.feature

@@ -161,3 +161,16 @@ Feature: run features with nested steps
       """
     When I run feature suite
     Then the suite should have passed
+
+  Scenario: BeforeStep used for multisteps
+    Given a feature "normal.feature" file:
+      """
+      Feature: normal feature
+
+        Scenario: invoke BeforeStep in multistep
+          Given I allow variable injection 
+          And I run multisteps that set a value
+          Then the stored value is "someverylonginjectionsoweacanbesureitsurpasstheinitiallongeststeplenghtanditwillhelptestsmethodsafety"
+      """
+    When I run feature suite
+    Then the suite should have passed

run_test.go

@@ -518,11 +518,11 @@ func Test_AllFeaturesRun(t *testing.T) {
 ...................................................................... 140
 ...................................................................... 210
 ...................................................................... 280
-.......................................................                335
+..........................................................             338
 
 
-88 scenarios (88 passed)
-335 steps (335 passed)
+89 scenarios (89 passed)
+338 steps (338 passed)
 0s
 `
 
@@ -545,11 +545,11 @@ func Test_AllFeaturesRunAsSubtests(t *testing.T) {
 ...................................................................... 140
 ...................................................................... 210
 ...................................................................... 280
-.......................................................                335
+..........................................................             338
 
 
-88 scenarios (88 passed)
-335 steps (335 passed)
+89 scenarios (89 passed)
+338 steps (338 passed)
 0s
 `
 

suite_context_test.go

@@ -141,6 +141,12 @@ func InitializeScenario(ctx *ScenarioContext) {
 		}
 	})
 
+	ctx.Step(`I store value "([^"]*)"$`, tc.iStoreValue)
+	ctx.Step(`^the stored value is "([^"]*)"$`, tc.theStoredValueIs)
+	ctx.Step(`^I run multisteps that set a value$`, func() Steps {
+		return Steps{`I store value "{{X}}"`}
+	})
+
 	ctx.StepContext().Before(tc.inject)
 }
 
@@ -365,6 +371,23 @@ func (tc *godogFeaturesScenario) iShouldSeeTheContextInTheNextStep(ctx context.C
 	return nil
 }
 
+type valueContextKey struct{}
+
+func (tc *godogFeaturesScenario) iStoreValue(ctx context.Context, value string) context.Context {
+	return context.WithValue(ctx, valueContextKey{}, value)
+}
+
+func (tc *godogFeaturesScenario) theStoredValueIs(ctx context.Context, want string) error {
+	got, ok := ctx.Value(valueContextKey{}).(string)
+	if !ok {
+		return errors.New("context does not contain our key")
+	}
+	if got != want {
+		return fmt.Errorf("context has the wrong value for our key: got %s, want %s", got, want)
+	}
+	return nil
+}
+
 func (tc *godogFeaturesScenario) followingStepsShouldHave(status string, steps *DocString) error {
 	var expected = strings.Split(steps.Content, "\n")
 	var actual, unmatched, matched []string