/api/user/add
{
    username:"",
    password:"",
    confirmpassword:""
}

/api/user/authenticate
{
    username:"",
    password:""
}

201 token
400

/api/user/update
token
{
    oldpassword:"",
    newpassword:"",
    confirmpassword:""
}

/api/user/delete
token
{
    username:"",
    password:""
}

/api/expense/add
token
{
    name:
    amount:
    datetime:(optional)
    tags:
}

/api/expense/update
token
{
    id:
    name: {optional}
    amount: {optional}
    datetime: (optional)
    tags: {optional}
}

/api/expense/delete
token
{
    id:
}

/api/expense/view
token
{
    id:
}

/api/expense/query
token