rename a unit test file

Change-Id: Iab4f1470911bcfff3972831175d1c5f052b58adf
diff --git a/tests/unit-tests/crypto-helper.t.cpp b/tests/unit-tests/crypto-helpers.t.cpp
similarity index 99%
rename from tests/unit-tests/crypto-helper.t.cpp
rename to tests/unit-tests/crypto-helpers.t.cpp
index ba644ae..febd0be 100644
--- a/tests/unit-tests/crypto-helper.t.cpp
+++ b/tests/unit-tests/crypto-helpers.t.cpp
@@ -25,7 +25,7 @@
 namespace ndncert {
 namespace tests {
 
-BOOST_AUTO_TEST_SUITE(TestCryptoHelper)
+BOOST_AUTO_TEST_SUITE(TestCryptoHelpers)
 
 BOOST_AUTO_TEST_CASE(EcdhWithRawKey)
 {