Fallback to --help when no command is entered after gocurl

**Actual**
```
redacted@redacted-MacBook-Pro ~ % gocurl
Failed to parse args: URL not found in the arguments: [gocurl]%  
```

**Expected**
```
redacted@ redacted-MacBook-Pro ~ % gocurl
gocurl: try 'gocurl --help' for more information
```