Remove psutil from dependencies.

Author: pglombardo

requirements.txt

@@ -2,5 +2,4 @@ nose>=1.0
 fysom>=2.1.2
 opentracing>=1.2.1
 basictracer>=2.2.0
-psutil>=5.1.3
 autowrapt>=1.0

setup.py

@@ -15,8 +15,7 @@
       install_requires=['autowrapt>=1.0',
                         'fysom>=2.1.2',
                         'opentracing>=1.2.1,<1.3',
-                        'basictracer>=2.2.0',
-                        'psutil>=5.1.3'],
+                        'basictracer>=2.2.0'],
       entry_points={'django': ['django.core.handlers.base = instana.django:hook'],
                     'django19': ['django.core.handlers.base = instana.django19:hook'],
                     'flask': ['flask = instana.flaskana:hook'],