tests: expect certificate name in KeyLocator

Also, delete unused KeyChainFixture::makeCert function.

refs #5112

Change-Id: I59b1ca81fca0481a37126270c447f639080ec75f
diff --git a/tests/key-chain-fixture.hpp b/tests/key-chain-fixture.hpp
index 9f03ea0..0ffcb0e 100644
--- a/tests/key-chain-fixture.hpp
+++ b/tests/key-chain-fixture.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2020,  Regents of the University of California,
+ * Copyright (c) 2014-2022,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -49,16 +49,6 @@
 
 public:
   /**
-   * @brief Creates and returns a certificate for a given key
-   * @param key The key for which to make a certificate
-   * @param issuer The IssuerId to include in the certificate name
-   * @param signingKey The key with which to sign the certificate; if not provided, the
-   *                   certificate will be self-signed
-   */
-  Certificate
-  makeCert(const Key& key, const std::string& issuer, const Key& signingKey = Key());
-
-  /**
    * @brief Saves an NDN certificate to a file
    * @return true if successful, false otherwise
    */