feat: add --source to contacts update

[notnmeyer]

• updates to loops-go v0.7.1
• adds --source flag to contacts update

➜ loops contacts update -h

  Update a contact

  USAGE


    loops contacts update [--flags]


  FLAGS

    --contact-props  Path to a JSON file of contact properties
    --debug          Print API request details before sending
    -e --email       Contact email address
    --first-name     First name
    -h --help        Help for update
    --last-name      Last name
    --list           Mailing list subscription as id=true|false (repeatable)
    -o --output      Output format (text, json) (text)
    --prop           Contact property as KEY=value (repeatable)
    --source         Source
    -s --subscribed  Subscribed status ("true" or "false")
    -t --team        Team key name to use
    --user-group     User group
    -u --user-id     User ID