Adds toBeCloseTo matcher with associated tests

[chowieuk]

Note: is as close to the Jest version as I could make it, but I had difficulty implementing some of the test cases, particularly those that threw Matcher errors, or used the rejects / resolves method. (https://github.com/facebook/jest/blob/94b73a2dd8bf8f6225769f2fe4a9322ac85483d8/packages/expect/src/tests/matchers.test.js) line 1692 through 1744 I'm not sure what the analogous version is for this library