Revert "Build JavaScript files during python package build" (#798)

This reverts commit bbad14e.

Reason for revert:
The change broke `sdist` (source distribution) installs
(which will attempt to run `make` even when *installing*,
but neither `Makefile` nor `package.json` are inlcuded in
the tarball (see `MANIFEST.in`), so the command will fail.

Author: ix5

setup.py

@@ -1,27 +1,12 @@
 #!/usr/bin/env python3
 # -*- encoding: utf-8 -*-
 
-import os
-import setuptools.command.build_py
-import subprocess
-
 from setuptools import setup, find_packages
 
 requires = ['itsdangerous', 'Jinja2', 'misaka>=2.0,<3.0', 'html5lib',
             'werkzeug>=1.0', 'bleach', 'Flask-Caching>=1.9', 'Flask']
 tests_require = ['pytest', 'pytest-cov']
 
-
-class NpmBuildCommand(setuptools.command.build_py.build_py):
-    """Prefix Python build with node-based asset build"""
-
-    def run(self):
-        # https://tox.wiki/en/latest/config.html#injected-environment-variables
-        if 'TOX_ENV_NAME' not in os.environ:
-            subprocess.check_call(['make', 'init', 'js'])
-        setuptools.command.build_py.build_py.run(self)
-
-
 setup(
     name='isso',
     version='0.12.5',
@@ -52,7 +37,4 @@ def run(self):
         'console_scripts':
             ['isso = isso:main'],
     },
-    cmdclass={
-        'build_py': NpmBuildCommand,
-    },
 )