internal: increase max allocations to 90.

This test passes in Go 1.6, but 1.4 is allocating ~88 per API call.
Once the SDK is based on 1.6 we can re-reduce the limit.

Change-Id: I514341b01f826524a092434d4844d3e8c30fef7d
diff --git a/internal/api_test.go b/internal/api_test.go
index 12da348..386d7f6 100644
--- a/internal/api_test.go
+++ b/internal/api_test.go
@@ -360,7 +360,8 @@
 	}
 
 	// Lots of room for improvement...
-	const min, max float64 = 70, 85
+	// TODO(djd): Reduce maximum to 85 once the App Engine SDK is based on 1.6.
+	const min, max float64 = 70, 90
 	if avg < min || max < avg {
 		t.Errorf("Allocations per API call = %g, want in [%g,%g]", avg, min, max)
 	}