Setting Script=True for binding=Binding.Exec fails build

[LehMaxence]

Both on Windows and Ubuntu 20.04 using python 3.9, running python setup.py develop on the hello-world example results in an error:

Traceback (most recent call last):
  File "/home/max/Repo/setuptools-rust/examples/hello-world/setup.py", line 4, in <module>
    setup(
...
  File "/opt/conda/envs/helloworld/lib/python3.9/site-packages/setuptools_rust/setuptools_ext.py", line 103, in run
    build_rust.run()
  File "/opt/conda/envs/helloworld/lib/python3.9/site-packages/setuptools_rust/command.py", line 52, in run
    self.run_for_extension(ext)
  File "/opt/conda/envs/helloworld/lib/python3.9/site-packages/setuptools_rust/build.py", line 93, in run_for_extension
    self.install_extension(ext, dylib_paths)
  File "/opt/conda/envs/helloworld/lib/python3.9/site-packages/setuptools_rust/build.py", line 309, in install_extension
    ext.install_script(ext_path)
  File "/opt/conda/envs/helloworld/lib/python3.9/site-packages/setuptools_rust/extension.py", line 173, in install_script
    f.write(TMPL.format({"name": name}))
KeyError: 'name'

[messense]

Duplicated of #153 , fixed in #154.