Removed support for py2.7

Author: ddetommaso

setup.py

@@ -23,7 +23,6 @@
     keywords=['eye-tracker','tobii','glasses', 'tobii pro glasses 2', 'tobii glasses', 'eye tracking'],
     packages=find_packages(exclude=['examples*']),
     classifiers = [
-                'Programming Language :: Python :: 2.7',
                 'Programming Language :: Python :: 3.5',
                 'Programming Language :: Python :: 3.6',
                 'Programming Language :: Python :: 3.7',