FIX: Remove architecture and math optimizations from compiler

Architecture and math optimization settings work well when installing
locally, but are not portable to other architectures. This removes
those optimizations to err in the favor of portability.

setup.py

@@ -24,10 +24,11 @@
 # Add the directory where the files are located
 msis2_sources = [os.path.join('src', 'msis2', x) for x in msis2_sources]
 
+# If you want to get some additional speed from compile-time options you can
+# add extra compile-time flags. e.g., '-march=native', '-ffast-math'
 ext_msis2 = Extension(name='pymsis.msis2f',
                       sources=msis2_sources,
-                      extra_f90_compile_args=['-std=legacy', '-march=native',
-                                              '-ffast-math'])
+                      extra_f90_compile_args=['-std=legacy'])
 
 msis00_sources = [os.path.join('src', 'msis00', 'msis00.F90'),
                   os.path.join('src', 'msis00', 'NRLMSISE-00.FOR')]