Prep for 0.4.0 release

Author: sverhoeven

CITATION.cff

@@ -79,4 +79,4 @@ license: Apache-2.0
 message: "If you use this software, please cite it using these metadata."
 repository-code: "https://github.com/NLeSC/python-template"
 title: "Netherlands eScience Center Python Template"
-version: "0.3.0"
+version: "0.4.0"

setup.cfg

@@ -23,7 +23,7 @@ name = Netherlands eScience Center Python Template
 project_urls =
     Bug Tracker = https://github.com/NLeSC/python-template/issues
 url = https://github.com/NLeSC/python-template
-version = 0.3.0
+version = 0.4.0
 
 
 [options]