Revert to using unofficial pybedtools.

requirements.txt

@@ -6,8 +6,8 @@ numpy
 pandas
 pyBigWig
 # pybedtools @ git+https://github.com/blaiseli/pybedtools.git@fix_missing_headers --global-option="cythonize"
-# pybedtools @ git+https://github.com/blaiseli/pybedtools.git@pep518
-pybedtools
+pybedtools @ git+https://github.com/blaiseli/pybedtools.git@pep518
+# pybedtools
 # scipy<=1.3.3
 scipy>=1.4.2
 seaborn

setup.py

@@ -45,8 +45,8 @@ setup(
         "numpy",
         "pandas",
         "pyBigWig",
-        # "pybedtools @ git+https://github.com/blaiseli/pybedtools.git@pep518",
-        "pybedtools",
+        "pybedtools @ git+https://github.com/blaiseli/pybedtools.git@pep518",
+        # "pybedtools",
         # "scipy<=1.3.3",
         "scipy>=1.4.2",
         "seaborn"],