Request parameters breaking when examples and copy has underscores

I've noticed an issue when there are underscores as part of the params in the resources.

Here's an example:

```
## Resource Title [/resource/{id}/info{?status,order_by,sort,page,per_page}]

+ Parameters
+ id: 64 (required, string) - user id or 'me'
+ status: paid (optional, string) - transaction status, one of pending, validated, paid, denied
+ order_by: transaction_date (optional, enum) - one of transaction_date, some_name, amount, user_status, status
+ sort: asc (optional, enum) - one of asc, desc
+ page: 1 (optional, integer) - pagination parameter
+ per_page: 5 (optional, integer) - pagination parameter
```

When running aglio against the above, I get the error:

```
>> Line 867: parameter 'order_by: transaction_date' not specified in 'Resource Title' its '/resource/{id}/info{?status,order_by,sort,page,per_page}' URI template (warning code 8)
```

But if I remove all the underscores from the "order_by" params and replace it with:

```
+ order_by: transactiondate (optional, enum) - one of transactiondate, somename, amount, userstatus, status
```

Then it works!
I think the parser is breaking on underscores as parameters.

Anyone else come across this before?