Update_recessions - being able to show only certain recession bands

[jmaltman]

Currently it doesn't look like you can choose which recession bands to include with update_recessions(). I tried adding this function to my plot, only wanting to show certain years, but this function forced the X axis to expand to include all recession bands. Being able to either adjust the X axis to only include the years (and therefore recession bands) or select the specific recession bands you want to include would be helpful.