Added yml file for cudatoolkit version 11.6 (#964)

Added yml file for cudatoolkit version11.6. 

No testcases required for this change.

Authors:
  - Alhad Deshpande (https://github.com/alhad-deshpande)

Approvers:
  - AJ Schmidt (https://github.com/ajschmidt8)
  - Mark Harris (https://github.com/harrism)

URL: #964

conda/environments/rmm_dev_cuda11.6.yml

@@ -0,0 +1,22 @@
+name: rmm_dev
+channels:
+- rapidsai
+- conda-forge
+dependencies:
+- clang=11.1.0
+- clang-tools=11.1.0
+- cmake>=3.20.1
+- cmake-format=0.6.11
+- flake8=3.8.3
+- black=19.10
+- isort=5.6.4
+- python>=3.7,<3.9
+- numba>=0.49
+- numpy
+- cffi>=1.10.0
+- pytest
+- cudatoolkit=11.6
+- spdlog>=1.8.5,<1.9
+- cython>=0.29,<0.30
+- gcovr>=5.0
+- cuda-python>=11.6,<12.0