CHG: updated changelog

CHANGELOG.md

@@ -1,11 +1,16 @@
 Changelog for `slurmfun`
 =======================
 
+[0.4] - 2020-05-11
+------------------
+* Added support for functions with multiple output arguments
+* Re-added support for functions without output arguments
+
 [0.3] - 2020-04-30
 ------------------
 * Added `'cpu'` and `'mem'` options to configure number of cores and memory
   for each job
 * Added option to specify a different partition for each job
 * slurmfun now tolerates a SLURM controller outage of up to 5 min
 * The MATLAB job can now be started with more than one thread
-* Printing of progress has been improved
+* Printing of progress has been improved