Respect csv ignore tag

[MJacred]

We auto-create structs using https://github.com/volatiletech/sqlboiler.
And load in data using e.g. csv via gocsv.

For sqlboiler to work, they have R and L fields. Those fields are other structs (or pointer to them). And the relation can circle.

This results for some structs in infinity loops.

Respecting the csv ignore "-" would resolve this.
This PR aims to do that.
After running our code we get no more infinity loops.

example output struct

type Pilot struct {
  ID   int    `boil:"id" json:"id" toml:"id" yaml:"id"`
  Name string `boil:"name" json:"name" toml:"name" yaml:"name"`

  R *pilotR `boil:"-" json:"-" toml:"-" yaml:"-"`
  L pilotR  `boil:"-" json:"-" toml:"-" yaml:"-"`
}

Probably fixes #168

[pikanezi]

Make sure that the tests pass, then I will merge it.

Thanks

[pikanezi]

thanks