Produce benchmark JSON schema v2

- No more '(Display)' strings in the GPU names, but store devices as
  `{'name': name, 'type': 'CPU/CUDA/OPENCL', 'is_display': bool}`
- Introduces testing with py.test & pipenv. The test suite is far from
  complete, though.

Pipfile

@@ -0,0 +1,14 @@
+[[source]]
+url = "https://pypi.org/simple"
+verify_ssl = true
+name = "pypi"
+
+[packages]
+requests = "*"
+
+[dev-packages]
+pytest = "*"
+pytest-cov = "*"
+
+[requires]
+python_version = "3.6"