Added env file and readme

README.md

+# Autotuning and Predictive Autotuning
+
+Performs autotuning on program approximation knobs using an error-predictive proxy in place of the
+original program, to greatly speedup autotuning while getting results comparable in quality.
+
+Work in progress.
+
+## Requirements
+
+Prerequisite packages are listed in `./env.yaml`. Conda is the validated and recommended way to set
+up a working environment. If you're using conda, do
+
+```bash
+conda env create -n predtuner -f env.yaml
+conda activate predtuner
+```

env.yaml

+name: predtuner
+channels:
+  - pytorch
+  - defaults
+dependencies:
+  - matplotlib=3.3.2
+  - networkx=2.5
+  - python=3.8.5
+  - pytorch=1.7.0
+  - torchvision=0.8.1
+  - tqdm=4.50.2
+  - pandas=1.1.3
+  - pip=20.2.4
+  - wheel=0.35.1
+  - jsonpickle=1.5
+  - pip:
+      - argparse
+      - opentuner==0.8.3  # Must be 0.8.3, they fixed an important bug
+      - sqlalchemy==1.3