[BUG] Unable to create working tarball

[mtwichan]

Description

Creating a tarball or wheel from the dash-cytoscape library builds, but does not install and work properly.

Steps/Code to Reproduce

Creating a tarball python setup.py sdist and installing pip install dash_cytoscape-0.3.0.tar.gz:

C:\Users\Dell\Desktop\Code\Zyphr\dash-cytoscape\dist>pip install dash_cytoscape-0.3.0.tar.gz
Processing c:\users\dell\desktop\code\zyphr\dash-cytoscape\dist\dash_cytoscape-0.3.0.tar.gz
    ERROR: Command errored out with exit status 1:
     command: 'c:\users\dell\appdata\local\programs\python\python39\python.exe' -c 'import io, os, sys, setuptools, tokenize; sys.argv[0] = '"'"'C:\\Users\\Dell\\AppData\\Local\\Temp\\pip-req-build-vjwdxxaw\\setup.py'"'"'; __file__='"'"'C:\\Users\\Dell\\AppData\\Local\\Temp\\pip-req-build-vjwdxxaw\\setup.py'"'"';f = getattr(tokenize, '"'"'open'"'"', open)(__file__) if os.path.exists(__file__) else io.StringIO('"'"'from setuptools import setup; setup()'"'"');code = f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' egg_info --egg-base 'C:\Users\Dell\AppData\Local\Temp\pip-pip-egg-info-gleh_o9b'
         cwd: C:\Users\Dell\AppData\Local\Temp\pip-req-build-vjwdxxaw\
    Complete output (5 lines):
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "C:\Users\Dell\AppData\Local\Temp\pip-req-build-vjwdxxaw\setup.py", line 7, in <module>
        with open('package.json') as f:
    FileNotFoundError: [Errno 2] No such file or directory: 'package.json'
    ----------------------------------------
WARNING: Discarding file:///C:/Users/Dell/Desktop/Code/Zyphr/dash-cytoscape/dist/dash_cytoscape-0.3.0.tar.gz. Command errored out with exit status 1: python setup.py egg_info Check the logs for full command output.
ERROR: Command errored out with exit status 1: python setup.py egg_info Check the logs for full command output.

Creating a wheel python setup.py bdist_wheel and installing pip install dash_cytoscape-0.3.0.tar.gz:

>>> import dash_cytoscape as cy
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/alex/plotly/dash-cytoscape/dash_cytoscape/__init__.py", line 23, in <module>
    with open(_filepath) as f:
FileNotFoundError: [Errno 2] No such file or directory: '/Users/alex/plotly/dash-cytoscape/dash_cytoscape/package-info.json'

Here are some hints from @alexcjohnson:

Presumably I can install it because it has a wheel (which is great! keep building wheels along with the sdist tarballs!). If I try to build as you did, I get a similar problem. Has this really been broken since 0.3.0 was released in May? Specifically I think we need to revert these two changes:

• looking for package.json in the root instead of inside the package dir
• calling it package-info.json instead of package.json when copied in there - ie keep the rest of the change to build:backends, just remove the -p package-info.json so it's still called package.json, because that's what's in MANIFEST.in and it's what's referenced in __init__.py

CC: @alexcjohnson @jackparmer @kinimesi