Various improvements to setup.py (#262)

Notably:
* The readme content is now included in PyPI
* Alan's name is no longer associated with Hugo's email address
* The PyPI sidebar will now link to our issue tracker and documentation
* The __version__ loading is a little more resilient to unusual value of cwd

Author: eric-wieser

setup.py

@@ -1,36 +1,47 @@
 #!/usr/bin/env python
 from setuptools import setup, find_packages
-import os
+from os import path
 
-version_path = os.path.join('galgebra', '_version.py')
-exec(open(version_path).read())
+this_directory = path.abspath(path.dirname(__file__))
 
-LONG_DESCRIPTION = """
-Symbolic Geometric Algebra/Calculus package for SymPy. BSD License.
-"""
+with open(path.join(this_directory, 'galgebra', '_version.py'), encoding='utf-8') as f:
+    exec(f.read())
 
-setup(name='galgebra',
-      version=__version__,  # noqa: F821
-      description='Symbolic Geometric Algebra/Calculus package for SymPy.',
-      author='Alan Bromborsky',
-      author_email='[email protected]',
-      url='https://github.com/pygae/galgebra',
-      license='BSD',
-      packages=find_packages(),
-      package_dir={'galgebra': 'galgebra'},
-      install_requires=['sympy'],
-      python_requires='>=3.5.*',
-      long_description=LONG_DESCRIPTION,
-      classifiers=[
-            'Development Status :: 4 - Beta',
-            'Environment :: Console',
-            'Intended Audience :: Science/Research',
-            'License :: OSI Approved :: BSD License',
-            'Natural Language :: English',
-            'Operating System :: OS Independent',
-            'Programming Language :: Python :: 3.5',
-            'Programming Language :: Python :: 3.6',
-            'Programming Language :: Python :: 3.7',
-            'Programming Language :: Python :: 3.8',
-            'Topic :: Scientific/Engineering :: Mathematics',
-            'Topic :: Scientific/Engineering :: Physics'])
+with open(path.join(this_directory, 'README.md'), encoding='utf-8') as f:
+    long_description = f.read()
+
+setup(
+    name='galgebra',
+    version=__version__,  # noqa: F821
+    description='Symbolic Geometric Algebra/Calculus package for SymPy.',
+    author='Alan Bromborsky',
+    maintainer='Hugo Hadfield',
+    maintainer_email='[email protected]',
+    url='https://github.com/pygae/galgebra',
+    license='BSD',
+    packages=find_packages(),
+    package_dir={'galgebra': 'galgebra'},
+    install_requires=['sympy'],
+    python_requires='>=3.5.*',
+    long_description=long_description,
+    long_description_content_type='text/markdown',
+    classifiers=[
+        'Development Status :: 4 - Beta',
+        'Environment :: Console',
+        'Intended Audience :: Science/Research',
+        'License :: OSI Approved :: BSD License',
+        'Natural Language :: English',
+        'Operating System :: OS Independent',
+        'Programming Language :: Python :: 3.5',
+        'Programming Language :: Python :: 3.6',
+        'Programming Language :: Python :: 3.7',
+        'Programming Language :: Python :: 3.8',
+        'Topic :: Scientific/Engineering :: Mathematics',
+        'Topic :: Scientific/Engineering :: Physics',
+    ],
+    project_urls={
+        'Documentation': 'http://galgebra.readthedocs.io',
+        'Bug Tracker': 'https://github.com/pygae/galgebra/issues',
+        'Source Code': 'https://github.com/pygae/galgebra',
+    },
+)