feature: fill in required python metainfo

Author: shenek

Cargo.toml

@@ -10,13 +10,26 @@ keywords = ["json", "python", "splitter"]
 repository = "https://github.com/shenek/python-streamson"
 categories = ["parsing"]
 
+[package.metadata.maturin]
+classifier = [
+    "Development Status :: 4 - Beta",
+    "Intended Audience :: Developers",
+    "License :: OSI Approved :: MIT License",
+    "License :: OSI Approved",
+    "Operating System :: MacOS",
+    "Operating System :: Microsoft :: Windows",
+    "Operating System :: POSIX :: Linux",
+    "Programming Language :: Python :: 3.6",
+    "Programming Language :: Python :: 3.7",
+    "Programming Language :: Python :: 3.8",
+    "Programming Language :: Python",
+    "Programming Language :: Rust",
+]
+
 [lib]
 name = "streamson"
 crate-type = ["cdylib"]
 
-[package.metadata.maturin]
-classifier = ["Programming Language :: Python"]
-
 [dependencies]
 pyo3 = { version = "0.10", features = ["extension-module"] }
 streamson-lib = "0.2.0"