Feature: Pretty messages

[Dzejkop]

Catch does this

Scenario: vectors can be sized and resized
     Given: A vector with some items
      When: more capacity is reserved
      Then: the capacity changes but not the size

catchr will show you the path to the test, but paths cannot contain any special characters. It'd be nice to be able to do something like:

section "Very descriptive comment" {
	case "-- special chars ???" {
		assert!(false, catchr_msg!());
	}
}

and for it to output:

running 1 test
test very_descriptive_comment::special_chars ... FAILED

failures:

---- very_descriptive_comment::special_chars stdout ----
thread 'very_descriptive_comment::special_chars' panicked at '
Section: Very descriptive comment
	Case: -- special chars ???
', src/lib.rs:4:9

or something simmilar