#506 Use Pipenv

This is a workaround regarding Poetry's bug. If there are two identically constrained version specification, Poetry attempts to resolve dependency versions for every constraints combination, even if there's no intersection, which raises SolverProblemError. This behaviour isn't fixed yet but tracked in <python-poetry/poetry#3367> and will be resolved in <python-poetry/poetry#4695>.

Pipfile

@@ -0,0 +1,26 @@
+[[source]]
+url = "https://pypi.python.org/simple"
+verify_ssl = true
+name = "pypi"
+
+[packages]
+astropy = ">=3.0, <6.0"
+matplotlib = ">=3.3, <4.0"
+n_const = ">=1.0.4, <2.0"
+neclib = ">=0.3.1, <1.0"
+numpy = ">=1.19, <2.0"
+pandas = ">=0.25, <2.0"
+scipy = ">=1.5, <2.0"
+typing-extensions = { version = ">=3.10, <4.0", markers="python_version < '3.8'" }
+
+[dev-packages]
+pytest = ">=5.2, <6.0"
+black = ">=20.8b, <23"
+flake8 = ">=3.8, <4.0"
+ipykernel = ">=5.3, <6.0"
+m2r2 = ">=0.2, <2.0"
+pydata-sphinx-theme = ">=0.4, <2.0"
+sphinx = ">=3.3, <4.0"
+
+[requires]
+python_version = "3.7"