Move version into setup.py and read it back with pkg_resources

meanas/__init__.py

@@ -41,8 +41,10 @@ Dependencies:
 
 """
 
+import pkg_resources
+
 from .types import dx_lists_t, field_t, vfield_t, field_updater
 from .vectorization import vec, unvec
 
 __author__ = 'Jan Petykiewicz'
-version = '0.5'
+__version__ = pkg_resources.get_distribution('meanas').version

setup.py

@@ -1,13 +1,12 @@
 #!/usr/bin/env python3
 
 from setuptools import setup, find_packages
-import meanas
 
 with open('README.md', 'r') as f:
     long_description = f.read()
 
 setup(name='meanas',
-      version=meanas.version,
+      version='0.5',
       description='Electromagnetic simulation tools',
       long_description=long_description,
       long_description_content_type='text/markdown',