add conda badge (#1424)

README.md

@@ -10,6 +10,7 @@ Cognite Python SDK
 [![codecov](https://codecov.io/gh/cognitedata/cognite-sdk-python/branch/master/graph/badge.svg)](https://codecov.io/gh/cognitedata/cognite-sdk-python)
 [![Documentation Status](https://readthedocs.com/projects/cognite-sdk-python/badge/?version=latest)](https://cognite-sdk-python.readthedocs-hosted.com/en/latest/)
 [![PyPI version](https://badge.fury.io/py/cognite-sdk.svg)](https://pypi.org/project/cognite-sdk/)
+[![conda version](https://anaconda.org/conda-forge/cognite-sdk/badges/version.svg)](https://anaconda.org/conda-forge/cognite-sdk)
 [![mypy](http://www.mypy-lang.org/static/mypy_badge.svg)](http://mypy-lang.org)
 [![Code style: black](https://img.shields.io/badge/code%20style-black-000000.svg)](https://github.com/ambv/black)