more setup.py cleanup

setup.py

 from setuptools import setup, Extension
-
 import sys
-import sysconfig
-import os.path
-import distutils.sysconfig
 
 
 class _deferred_pybind11_include(object):
@@ -16,20 +12,19 @@ class _deferred_pybind11_include(object):
 
 
 extra_compile_args = []
-include_dirs = ['./', _deferred_pybind11_include(),
-                _deferred_pybind11_include(True)]
+include_dirs = ['./', _deferred_pybind11_include(True),
+                _deferred_pybind11_include()]
 
 python_module_link_args = []
-base_library_link_args = []
 
 if sys.platform == 'darwin':
+    import distutils.sysconfig
     extra_compile_args += ['--std=c++11', '--stdlib=libc++', '-mmacosx-version-min=10.9']
     vars = distutils.sysconfig.get_config_vars()
     vars['LDSHARED'] = vars['LDSHARED'].replace('-bundle', '')
     python_module_link_args+=['-bundle']
-    base_library_link_args+=['-dynamiclib']
 else:
-    extra_compile_args += ['--std=c++11', '-march=native', '-O3', '-Wfatal-errors', '-Wno-ignored-attributes', '-DPOCKETFFT_OPENMP', '-fopenmp', '-Wfloat-conversion' ,'-Wsign-conversion', '-Wconversion' ,'-W', '-Wall']
+    extra_compile_args += ['--std=c++11', '-march=native', '-O3', '-Wfatal-errors', '-Wno-ignored-attributes', '-DPOCKETFFT_OPENMP', '-fopenmp', '-Wfloat-conversion' ,'-Wsign-conversion', '-Wconversion' ,'-W', '-Wall', '-s']
     python_module_link_args += ['-march=native', '-Wl,-rpath,$ORIGIN', '-fopenmp']
 
 
@@ -49,7 +44,7 @@ setup(name='pypocketfft',
       author='Martin Reinecke',
       author_email='martin@mpa-garching.mpg.de',
       packages=[],
-      setup_requires=['numpy>=1.10.4', 'pybind11>=2.2.1'],
+      setup_requires=['numpy>=1.15.0', 'pybind11>=2.2.4'],
       ext_modules=get_extension_modules(),
-      install_requires=['numpy>=1.10.4', 'pybind11>=2.2.1']
+      install_requires=['numpy>=1.15.0', 'pybind11>=2.2.4']
       )