Pricing data.

Column	Type	Constraint	Description
shop	TEXT	PRIMARY KEY	Shop ID. (shop.username)
id	INTEGER		Identifier.
beginning	TIMESTAMP	NOT NULL	Beginning time. (inclusive)
ending	TIMESTAMP	NOT NULL	Ending time. (exclusive)
type	INTEGER	NOT NULL	Type. 0: Relative (advance/reduction) 1: Uniformity (flat fare) 2: Ratio
value	INTEGER	NOT NULL	Value. Meaning differs by "type."

CREATE TABLE pricing(
shop       TEXT,
id         INTEGER,
beginning  TIMESTAMP  NOT NULL,
ending     TIMESTAMP  NOT NULL,
value      INTEGER    NOT NULL,
type       INTEGER    NOT NULL,
PRIMARY KEY (shop, id)
);