Fix python_requires syntax, increment version to 0.29

Author: nathantspencer

setup.py

@@ -7,14 +7,14 @@
 
 setup(
     name="swick",
-    version="0.28",
+    version="0.29",
     description="The slick way to process SWC files.",
     long_description=long_description,
     long_description_content_type='text/markdown',
     author="Nathan T. Spencer",
     author_email="nathantspencer@gmail.com",
     url="https://nathantspencer.com",
-    python_requires=">=3.**",
+    python_requires=">=3.0",
     install_requires=[''],
     packages=['swick'],
     package_data={