Change build system to flit

setuptools does not have functionality for editable entry points, which
will be very useful for developing the CLI script. As such, I am
switching this project over to flit.

Pipfile

@@ -20,6 +20,7 @@ pytest = "*"
 pytest-cov = "*"
 tox = "*"
 isort = "*"
+flit = "*"
 
 [requires]
 python_version = "3.8"

pyproject.toml

@@ -1,6 +1,6 @@
 [build-system]
-requires = ["setuptools>=61.0", "wheel"]
-build-backend = "setuptools.build_meta"
+requires = ["flit_core >=3.2,<4"]
+build-backend = "flit_core.buildapi"
 
 [project]
 name = "macta_tools"

src/macta_tools/__init__.py

@@ -1,5 +1,5 @@
 from macta_tools import tools, utils
 from macta_tools._annotate import annotate
-from macta_tools._cli import run_from_cli
 
-__all__ = ['annotate', 'tools', 'utils', 'run_from_cli']
+__all__ = ['annotate', 'tools', 'utils']
+__version__ = '0.0.4'