Merge branch 'python_3.8' into 'master'

Increasing the minimal Python version

Closes #21

See merge request !259

binder/environment.yml

@@ -14,7 +14,7 @@
 name: pystencils
 dependencies:
   # Basic dependencies:
-  - python >= 3.6
+  - python >= 3.8
   - numpy
   - sympy >= 1.1
   - appdirs # to find default cache directory on each platform

doc/conf.py

@@ -51,7 +51,7 @@ nbsphinx_execute = 'never'
 nbsphinx_codecell_lexer = 'python3'
 
 # Example configuration for intersphinx: refer to the Python standard library.
-intersphinx_mapping = {'python': ('https://docs.python.org/3.6', None),
+intersphinx_mapping = {'python': ('https://docs.python.org/3.8', None),
                        'numpy': ('https://docs.scipy.org/doc/numpy/', None),
                        'matplotlib': ('https://matplotlib.org/', None),
                        'sympy': ('https://docs.sympy.org/latest/', None),

setup.py

@@ -134,6 +134,6 @@ setuptools.setup(name='pystencils',
                                 'ipython',
                                 'randomgen>=1.18'],
 
-                 python_requires=">=3.6",
+                 python_requires=">=3.8",
                  cmdclass=get_cmdclass()
                  )