Change YAML to JSON

lib/pleroma/emoji.ex

lib/pleroma/web/emoji_api/emoji_api_controller.ex

mix.exs

mix.lock

test/instance_static/emoji/test_pack/pack.json

test/instance_static/emoji/test_pack/pack.yml

test/instance_static/emoji/test_pack_nonshared/pack.json

test/instance_static/emoji/test_pack_nonshared/pack.yml

test/web/emoji_api_controller_test.exs