EGAssertEqual() with accuracy

Added a new assertion EGAssertEqual() that adds an accuracy parameter for approximate comparison.

Improve check, and some assertions

The check() function is now variadic (an array of examples is allowed but no longer required). It has a new form that calls functions that throw.

Added EGAssertEqual(), similar to XCTAssertEqual.

Added EGAssertThrowsError(), similar to XCTAssertThrowsError.

Documentation and environment updates

• Improved documentation
• Dropped .swiftpm directory
• Added .swiftpm to .gitignore
• Drop unneeded references to Foundation

Change names in EG and eg()

0.3.0

Revised to make EG's fields public, remove Package from name.

0.2.0

First public release of EGTest, a parameterized testing package for Swift

Provides a struct EG that can hold inputs and outputs, and some extension methods for XCTestCase to run the tests. See the README.