Remove assert_that()
Update wiki
Merge branch 'release/1.3' of https://github.com/elliotchance/concise into 1.3/144-remove-assert-that

Conflicts:
	README.md
Merge pull request #144 from elliotchance/1.3/144-remove-assert-that

Remove assert_that()
Merge branch 'release/1.3' of https://github.com/elliotchance/concise into 1.3/83-on-error-clause

Conflicts:
	wiki