Update setup.cfg for releasing 0.3.0

setup.cfg

@@ -7,7 +7,7 @@
 
 [metadata]
 name = empyre
-version = 0.2.1
+version = 0.3.0
 author = Jan Caron
 author-email = j.caron@fz-juelich.de
 description = Electron Microscopy Python Reconstruction
@@ -19,7 +19,9 @@ classifiers =
     Intended Audience :: Developers
     Intended Audience :: Science/Research
     License :: OSI Approved :: GNU General Public License v3 (GPLv3)
+    Programming Language :: Python :: 3.8
     Programming Language :: Python :: 3.7
+    Programming Language :: Python :: 3.6
     Topic :: Scientific/Engineering
     Operating System :: OS Independent
 keywords =