api/storage_service: Add get_release_version
api/storage_service: Add get_release_version

$ curl -X GET --header "Accept: application/json"
"http://127.0.0.1:10000/storage_service/release_version"

"2.1.8"

kjniemi/scylla,stamhe/scylla,raphaelsc/scylla,acbellini/scylla,victorbriz/scylla,tempbottle/scylla,scylladb/scylla,gwicke/scylla,senseb/scylla,gwicke/scylla,dwdm/scylla,kangkot/scylla,bowlofstew/scylla,glommer/scylla,phonkee/scylla,linearregression/scylla,raphaelsc/scylla,kangkot/scylla,respu/scylla,shaunstanislaus/scylla,phonkee/scylla,duarten/scylla,acbellini/scylla,asias/scylla,wildinto/scylla,senseb/scylla,avikivity/scylla,guiquanz/scylla,bowlofstew/scylla,victorbriz/scylla,eklitzke/scylla,asias/scylla,eklitzke/scylla,bowlofstew/scylla,tempbottle/scylla,respu/scylla,respu/scylla,rentongzhang/scylla,capturePointer/scylla,duarten/scylla,rluta/scylla,capturePointer/scylla,duarten/scylla,kangkot/scylla,capturePointer/scylla,stamhe/scylla,glommer/scylla,wildinto/scylla,gwicke/scylla,kjniemi/scylla,justintung/scylla,victorbriz/scylla,justintung/scylla,stamhe/scylla,shaunstanislaus/scylla,scylladb/scylla,asias/scylla,acbellini/scylla,shaunstanislaus/scylla,wildinto/scylla,eklitzke/scylla,scylladb/scylla,avikivity/scylla,avikivity/scylla,dwdm/scylla,aruanruan/scylla,linearregression/scylla,linearregression/scylla,rentongzhang/scylla,phonkee/scylla,senseb/scylla,rentongzhang/scylla,scylladb/scylla,kjniemi/scylla,raphaelsc/scylla,guiquanz/scylla,rluta/scylla,justintung/scylla,guiquanz/scylla,dwdm/scylla,tempbottle/scylla,aruanruan/scylla,rluta/scylla,glommer/scylla,aruanruan/scylla