Specify Minimum Python Version as 3.8 in package (#253)

* Add minimum python version 3.8 to setup.py configuration

* Add Python Programming Language classifiers to setup.py config

* Update minimum version of merlin-core to 0.8.0

* Revert change to merlin-core min version (feast/dask conflict)

setup.py

@@ -72,12 +72,17 @@ def read_requirements(req_path, filename):
     classifiers=[
         "Development Status :: 4 - Beta",
         "Programming Language :: Python :: 3",
+        "Programming Language :: Python :: 3.8",
+        "Programming Language :: Python :: 3.9",
+        "Programming Language :: Python :: 3.10",
+        "Programming Language :: Python :: 3 :: Only",
         "Intended Audience :: Developers",
         "License :: OSI Approved :: Apache Software License",
         "Topic :: Software Development :: Libraries",
         "Topic :: Scientific/Engineering",
     ],
     zip_safe=False,
+    python_requires=">=3.8",
     install_requires=requirements["cpu"],
     extras_require={
         **requirements,