Remove demo galleries from boop

photos/2013_08_2013_12_Trondheim/metadata.yml

----
-name: "3. Trondheim"
-cover: "DSC00179.jpg"

photos/2013_08_Bergen/metadata.yml

----
-name: "1. Bergen"
-cover: "DSC00100.jpg"

photos/2013_08_hiking_five_fifty_two/metadata.yml

----
-name: "2. Hiking five fifty-two"
-cover: "DSC00133.jpg"

photos/2013_09_5_hours_walk/metadata.yml

----
-name: "4. 5 hours walk"
-cover: "DSC00302.jpg"

photos/2013_12_Prague/metadata.yml

----
-name: "5. Prague"
-cover: "DSC00425.jpg"

photos/2015_03-2015_04-Tour_de_France/metadata.yml

----
-name: "6. Tour de France"
-cover: "07_Blois_02542.jpg"

photos/2015_05-2015_06_Tour_Europe/metadata.yml

----
-name: "7. Tour d’Europe"
-cover: "06_Tchou_tchou_03411.jpg"

photos/2017-05_2017-06_Royaume_Uni/metadata.yml

----
-name: "8. Royaume-Uni"
-cover: "DSC03695.JPG"

photos/2018-06_Moucheraclette/metadata.yml

----
-name: "Moucheraclette"
-cover: "DSC04034.JPG"
-password: ENV['BOOP_MOUCHERACLETTE_PASSWORD']

photos/2019-05-05_vercors/metadata.yml

----
-name: "9. Vercors"
-cover: "DSC04134.JPG"

photos/pain/metadata.yml

----
-name: "Le goût du pain"
-cover: "20190415_161925.jpg"