Remove picocoin reference configuration

Picocoin is no longer actively supported by the library, so the reference
configuration used in testing has been removed.
diff --git a/ChangeLog b/ChangeLog
index a6fa6bb..ab1ed29 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -113,6 +113,7 @@
    * Only run AES-192 self-test if AES-192 is available. Fixes #963.
    * Tighten the RSA PKCS#1 v1.5 signature verification code and remove the
      undeclared dependency of the RSA module on the ASN.1 module.
+   * Removed support for the library reference configuration for picocoin.
 
 = mbed TLS 2.6.0 branch released 2017-08-10
 
diff --git a/configs/config-picocoin.h b/configs/config-picocoin.h
deleted file mode 100644
index 26b24a9..0000000
--- a/configs/config-picocoin.h
+++ /dev/null
@@ -1,71 +0,0 @@
-/*
- *  Reduced configuration used by Picocoin.
- *
- *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
- *  SPDX-License-Identifier: Apache-2.0
- *
- *  Licensed under the Apache License, Version 2.0 (the "License"); you may
- *  not use this file except in compliance with the License.
- *  You may obtain a copy of the License at
- *
- *  http://www.apache.org/licenses/LICENSE-2.0
- *
- *  Unless required by applicable law or agreed to in writing, software
- *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
- *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- *  See the License for the specific language governing permissions and
- *  limitations under the License.
- *
- *  This file is part of mbed TLS (https://tls.mbed.org)
- */
-/*
- * Reduced configuration used by Picocoin.
- *
- * See README.txt for usage instructions.
- *
- * Distinguishing features:
- * - no SSL/TLS;
- * - no X.509;
- * - ECDSA/PK and some other chosen crypto bits.
- */
-
-#ifndef MBEDTLS_CONFIG_H
-#define MBEDTLS_CONFIG_H
-
-/* System support */
-#define MBEDTLS_HAVE_ASM
-#define MBEDTLS_HAVE_TIME
-
-/* mbed TLS feature support */
-#define MBEDTLS_CIPHER_MODE_CBC
-#define MBEDTLS_CIPHER_PADDING_PKCS7
-#define MBEDTLS_ECP_DP_SECP256K1_ENABLED
-#define MBEDTLS_ECDSA_DETERMINISTIC
-#define MBEDTLS_PK_PARSE_EC_EXTENDED
-#define MBEDTLS_ERROR_STRERROR_DUMMY
-#define MBEDTLS_FS_IO
-
-/* mbed TLS modules */
-#define MBEDTLS_AESNI_C
-#define MBEDTLS_AES_C
-#define MBEDTLS_ASN1_PARSE_C
-#define MBEDTLS_ASN1_WRITE_C
-#define MBEDTLS_BASE64_C
-#define MBEDTLS_BIGNUM_C
-#define MBEDTLS_ECDSA_C
-#define MBEDTLS_ECP_C
-#define MBEDTLS_ENTROPY_C
-#define MBEDTLS_HMAC_DRBG_C
-#define MBEDTLS_MD_C
-#define MBEDTLS_OID_C
-#define MBEDTLS_PADLOCK_C
-#define MBEDTLS_PK_C
-#define MBEDTLS_PK_PARSE_C
-#define MBEDTLS_PK_WRITE_C
-#define MBEDTLS_RIPEMD160_C
-#define MBEDTLS_SHA1_C
-#define MBEDTLS_SHA256_C
-
-#include "mbedtls/check_config.h"
-
-#endif /* MBEDTLS_CONFIG_H */
diff --git a/tests/scripts/test-ref-configs.pl b/tests/scripts/test-ref-configs.pl
index a9a89f1..79bacd4 100755
--- a/tests/scripts/test-ref-configs.pl
+++ b/tests/scripts/test-ref-configs.pl
@@ -23,8 +23,6 @@
     'config-suite-b.h' => {
         'compat' => "-m tls1_2 -f 'ECDHE-ECDSA.*AES.*GCM' -p mbedTLS",
     },
-    'config-picocoin.h' => {
-    },
     'config-ccm-psk-tls1_2.h' => {
         'compat' => '-m tls1_2 -f \'^TLS-PSK-WITH-AES-...-CCM-8\'',
     },