Make project python package friendly

- Add setup.py
- Move classes to module files
- Move tests folder inside module folder

setup.py

@@ -0,0 +1,40 @@
+import setuptools
+
+from stree import __author__, __version__
+
+
+def readme():
+    with open('README.md') as f:
+        return f.read()
+
+
+setuptools.setup(
+    name='STree',
+    version=__version__,
+    license='MIT License',
+    description='a python interface to oblique decision tree implementations',
+    long_description=readme(),
+    long_description_content_type='text/markdown',
+    packages=['stree'],
+    url='https://github.com/doctorado-ml/stree',
+    author=__author__,
+    author_email='ricardo.montanana@alu.uclm.es',
+    keywords='scikit-learn oblique-classifier oblique-decision-tree decision-tree svm svc',
+    classifiers=[
+        'Development Status :: 4 - Beta',
+        'License :: OSI Approved :: MIT License',
+        'Programming Language :: Python :: 3.7',
+        'Natural Language :: English',
+        'Topic :: Scientific/Engineering :: Artificial Intelligence',
+        'Intended Audience :: Science/Research'
+    ],
+    install_requires=[
+        'scikit-learn>=0.23.0',
+        'numpy',
+        'matplotlib',
+        'ipympl'
+    ],
+    data_files=[('data', ['data/.gitignore'])],
+    test_suite="stree.tests",
+    zip_safe=False
+)