MAINT: Update project classifiers in setup.py

This PR specifies the license as BSD, not only as OSI Approved. Further
it alters the Audience and Topic classifiers to better reflect the
financial audience of numpy-financial over regular numpy.

Author: Kai-Striega

setup.py

@@ -23,17 +23,19 @@ def get_version():
 
 CLASSIFIERS = """\
 Development Status :: 5 - Production/Stable
-Intended Audience :: Science/Research
 Intended Audience :: Developers
-License :: OSI Approved
+Intended Audience :: Financial and Insurance Industry
+License :: OSI Approved :: BSD License
 Programming Language :: Python
 Programming Language :: Python :: 3
 Programming Language :: Python :: 3.5
 Programming Language :: Python :: 3.6
 Programming Language :: Python :: 3.7
 Programming Language :: Python :: 3 :: Only
 Topic :: Software Development
-Topic :: Scientific/Engineering
+Topic :: Office/Business :: Financial :: Accounting
+Topic :: Office/Business :: Financial :: Investment
+Topic :: Office/Business :: Financial :: Spreadsheet
 """
 
 here = path.abspath(path.dirname(__file__))