TT#18776 add support to use a custom schema config file

* to use a custom schema config file:
        NGCP::Schema->new->connect({ config_file => 'filepath' });

    * it requires to look as:
        <config opt1="op1" opt2="opt2">
          <ngcp_connect_info>
            dsn...
          </ngcp_connect_info>

        </config>

Change-Id: I704ac7adfd9b1ecd431b4f51e76dc662711b69ae

lib/NGCP/Schema.pm

@@ -20,6 +20,9 @@ class_has('config', is => 'rw', isa => 'NGCP::Schema::Config', lazy => 1, defaul
 
 sub connection {
     my ($self, $cfg) = @_;
+    if ($cfg->{config_file}) {
+        $self->config->config_file($cfg->{config_file});
+    }
     unless(defined $cfg->{dsn}) {
         $cfg = $self->config->as_hash->{ngcp_connect_info};
     }