Changelog for is-0.4.3

-*-change-log-*- 2018-02-16 Víctor López Juan <victor@lopezjuan.com> * Version 0.4.1 * Make compatible with GHC 8.2.2 2017-02-01 Víctor López Juan <victor@lopezjuan.com> * Version 0.4 * Add stack support * Test for GHC 7.8.4, 7.10.3, 8.0.1 * Compile with -Werror 2014-11-23 Víctor López Juan <victor@lopezjuan.com> * Version 0.2 * Declare predicates from constructors of a data type 2014-11-20 Víctor López Juan <victor@lopezjuan.com> * Version 0.1 * Implement functions 'is(Not)?P?' * A few test cases * Short documentation