Clear ScanCode cache after installation

Author: soimkim

setup.py

@@ -4,6 +4,20 @@
 # SPDX-License-Identifier: Apache-2.0
 from codecs import open
 from setuptools import setup, find_packages
+from distutils.command.install import install as _install
+
+
+def _post_install(dir):
+    from subprocess import call
+    call(['scancode', '--reindex-licenses'])
+
+
+class install(_install):
+    def run(self):
+        _install.run(self)
+        self.execute(_post_install, (self.install_lib,),
+                     msg="Running post install task")
+
 
 with open('README.md', 'r', 'utf-8') as f:
     readme = f.read()
@@ -30,6 +44,7 @@
                      "Programming Language :: Python :: 3.8",
                      "Programming Language :: Python :: 3.9", ],
         python_requires=">=3.7",
+        cmdclass={'install': install},
         install_requires=required,
         extras_require={":python_version>'3.6'": ["scanoss>=0.7.0"],
                         ":python_version<'3.7'": ["dataclasses", "scanoss"]},