bank-lib testcase passes config file to the bank

src/bank-lib/bank.conf

@@ -0,0 +1,2 @@
+[taler]
+currency = KUDOS

src/bank-lib/test_bank_api.c

@@ -145,6 +145,7 @@ main (int argc,
                                    "taler-bank-manage",
                                    "taler-bank-manage",
                                    "--with-db", dbconn,
+                                   "-c", "bank.conf",
                                    "serve-http",
                                    "--port", "8080",
                                    NULL);