Added dependency listing in setup.py

setup.py

@@ -222,10 +222,6 @@ class DependenciesBuilder(_build):
         if sys.platform.startswith('win'):
             _print_error("You cannot build Spintrum on Windows. It is not supported.")
 
-        python_version = float(str(sys.version_info[0]) + "." + str(sys.version_info[1]))
-        if python_version < 3.3:
-            _print_error("You must have python version >= 3.3 to use Spintrum")
-
         check_programs_availability(["cmake","make","g++","gcc","gfortran","git","python3"])
 
         print("Building Spintrum C/C++ extension prerequisites")
@@ -256,6 +252,8 @@ setup(name='spintrum',
       author_email='samer@afach.de',
       license='MPL',
       packages=['spintrum'],
+      install_requires=['numpy', 'scipy', 'mpmath'],
+      python_requires = '>=3.3',
       include_package_data=True, # enable including files with MANIFEST.in
       package_data={'': [lib_file]},
       zip_safe=False,