load areas of interest into single `aois` table using `hstore`, starting with `sanctuaries`

[bbest]

Use PostgreSQL hstore to store the many varying fields of any given AOI feature into a single column, say attr, starting with load_sanctuaries.Rmd.

See:

• PostgreSQL hstore Tutorial

CREATE TABLE books (
    id serial primary key,
    title VARCHAR (255),
    attr hstore);

INSERT INTO books (title, attr)
VALUES
    ('PostgreSQL Tutorial',
      '"paperback" => "243",
       "publisher" => "postgresqltutorial.com",
       "language"  => "English",
       "ISBN-13"   => "978-1449370000",
           "weight"    => "11.2 ounces"');