No longer support Python 2.7

Author: rpanderson

setup.cfg

@@ -14,7 +14,7 @@ keywords = experiment control automation
 license = BSD
 classifiers =
     License :: OSI Approved :: BSD License
-    Programming Language :: Python :: 2.7
+    Programming Language :: Python :: 3 :: Only
     Programming Language :: Python :: 3.6
     Programming Language :: Python :: 3.7
     Programming Language :: Python :: 3.8
@@ -23,7 +23,7 @@ classifiers =
 zip_safe = False
 include_package_data = True
 packages = find:
-python_requires = >=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, !=3.5
+python_requires = >=3.6
 install_requires =
   blacs>=2.7.0
   labscript>=2.6.0