add yaml file for conda, to create basic environment for MetaSnk

envs/MetaSnk.yaml

+name: MetaSnk
+channels:
+  - defaults
+dependencies:cat 
+  - snakemake=5.5.0
+  - matplotlib=3.1.0=py36h5429711_0
+  - numpy=1.16.4=py36h7e9f1db_0
+  - numpy-base=1.16.4=py36hde5b4d6_0
+  - pandas=0.24.2=py36he6710b0_0
+  - pip=19.1.1=py36_0
+  - python=3.6.8=h0371630_0