CPU/GPU memory benchmarking utilities - Remove support for python 3.5 (now only 3.6+) (#3186)

* memory benchmark rss

* have both forward pass and line-by-line mem tracing

* cleaned up tracing

* refactored and cleaning up API

* no f-strings yet...

* add GPU mem logging

* fix GPU memory monitoring

* style and quality

* clean up and doc

* update with comments

* Switching to python 3.6+

* fix quality

setup.py

@@ -110,7 +110,7 @@ setup(
     ],
     extras_require=extras,
     scripts=["transformers-cli"],
-    python_requires=">=3.5.0",
+    python_requires=">=3.6.0",
     classifiers=[
         "Development Status :: 5 - Production/Stable",
         "Intended Audience :: Developers",
@@ -119,7 +119,6 @@ setup(
         "License :: OSI Approved :: Apache Software License",
         "Operating System :: OS Independent",
         "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.5",
         "Programming Language :: Python :: 3.6",
         "Programming Language :: Python :: 3.7",
         "Topic :: Scientific/Engineering :: Artificial Intelligence",