Add more tests

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snippets/6/t/post_empty_items.t

my $res2  = $test->request( POST '/api/v2/item', { text => '' } );
is $res2->content, '{"error":"No text provided"}';

my $res3  = $test->request( POST '/api/v2/item' );
is $res3->content, '{"error":"No text provided"}';

snippets/6/t/fetch_all_items_again.t

my $get3  = $test->request( GET '/api/v2/items');
my $items3 = decode_json($get3->content);
is scalar @{$items3->{items}}, 1;
is $items3->{items}[0]{text}, 'First Thing to do';

snippets/6/t/post_item_with_spaces.t

my $res4  = $test->request( POST '/api/v2/item', { text => '  one more  ' });
is_deeply decode_json($res4->content), { ok => 1, text => 'one more' };

my $get4  = $test->request( GET '/api/v2/items');
my $items4 = decode_json($get4->content);
is scalar @{$items4->{items}}, 2;
is $items4->{items}[0]{text}, 'First Thing to do';
is $items4->{items}[1]{text}, 'one more';