Allow newer brick/math versions

[tacman]

This widens the brick/math constraint to allow currently released 0.x versions through 0.17.

rowbot/url uses brick/math through BrickMathAdapter for integer host parsing operations. The adapter uses BigInteger construction, comparison, division, modulo, multiplication, addition, and power operations, and does not appear to rely on the APIs affected by newer brick/math breaking changes such as BigDecimal, BigRational, float inputs, or exception constructors.

This lets downstream consumers resolve newer compatible brick/math versions where their PHP/runtime constraints allow it.

Validation:

• composer validate --strict
• Local PHPUnit was not run because this fresh clone does not have dependencies installed.

[tacman]

Actually, I like #10 better. If needed, the application is responsible for installing it.