Add tests for writting SAN to CSR

Signed-off-by: Przemek Stekiel <przemyslaw.stekiel@mobica.com>
diff --git a/tests/data_files/Makefile b/tests/data_files/Makefile
index 7f39d31..61ed4de 100644
--- a/tests/data_files/Makefile
+++ b/tests/data_files/Makefile
@@ -1003,7 +1003,7 @@
 
 server1.req.sha256.ext: server1.key
 	# Generating this with OpenSSL as a comparison point to test we're getting the same result
-	openssl req -new -out $@ -key $< -subj '/C=NL/O=PolarSSL/CN=PolarSSL Server 1' -sha256 -addext "extendedKeyUsage=serverAuth"
+	openssl req -new -out $@ -key $< -subj '/C=NL/O=PolarSSL/CN=PolarSSL Server 1' -sha256 -addext "extendedKeyUsage=serverAuth" -addext "subjectAltName=URI:http://pki.example.com/,IP:127.1.1.0,DNS:example.com"
 all_final += server1.req.sha256.ext
 
 server1.req.sha384: server1.key