Tutorial not working - can't find provider for capability

Following the tutorial I got stuck with start the capability.

```
$ rosservice call /get_interfaces "{}" 
interfaces: ['minimal_pkg/Minimal']
$ rosservice call /get_providers "{}" 
providers: ['minimal_pkg/minimal', 'minimal_pkg/specific_minimal']
$ rosservice call /start_capability minimal_pkg/Minimal minimal_pkg/minimal
ERROR: service [/start_capability] responded with an error: error processing request: Capability Provider 'minimal_pkg/minimal' not found for Capability 'minimal_pkg/Minimal'
```