Skip header option within csv filter

[AbdulHaseebHussain]

Would it be possible to have an option for users to skip header lines should they wish to, similar to the autogenerate_column_names boolean option. Users generally implement this functionality themselves.

Could the drop filter plugin be called automatically if the skip header option is specified?

[tomrade]

I use the "exclude" option in filebeat for w3c files, but something similar could be nice here

[guyboertje]

Closing because #59