Add supported Python versions badge (#28)

Author: EmilieDel

README.md

@@ -52,6 +52,14 @@
 		</a>
 	</td>
 </tr>
+<tr>
+  <td>Python Versions</td>
+  <td>
+    <a href="https://pypi.org/project/atlalign/">
+    <img src="https://img.shields.io/pypi/pyversions/atlalign.svg" alt="Python Versions" />
+    </a>
+  </td>
+</tr>
 </table>
 
 Atlas Alignment is a toolbox to perform multimodal image registration. It 

setup.py

@@ -44,7 +44,13 @@
         "Development Status :: 4 - Beta",
         "License :: OSI Approved :: GNU Lesser General Public License v3 (LGPLv3)",
         "Operating System :: Unix",
+        "Programming Language :: Python",
         "Programming Language :: Python :: 3",
+        "Programming Language :: Python :: 3.6",
+        "Programming Language :: Python :: 3.7",
+        "Programming Language :: Python :: 3.8",
+        "Programming Language :: Python :: 3.9",
+        "Programming Language :: Python :: 3 :: Only",
         "Topic :: Scientific/Engineering :: Artificial Intelligence",
         "Topic :: Scientific/Engineering :: Image Processing",
         "Topic :: Software Development :: Libraries :: Python Modules",