Update atomicwrites from 1.1.5 to 1.2.0 (#3953)

requirements/dev.txt

@@ -41,7 +41,9 @@ isort==4.3.4 \
     --hash=sha256:b9c40e9750f3d77e6e4d441d8b0266cf555e7cdabdcff33c4fd06366ca761ef8
 
 # Required by pytest
-atomicwrites==1.1.5 --hash=sha256:a24da68318b08ac9c9c45029f4a10371ab5b20e4226738e150e6e7c571630ae6
+atomicwrites==1.2.0 \
+    --hash=sha256:6b5282987b21cd79151f51caccead7a09d0a32e89c568bd9e3c4aaa7bbdf3f3a \
+    --hash=sha256:e16334d50fe0f90919ef7339c24b9b62e6abaa78cd2d226f3d94eb067eb89043
 attrs==18.1.0 \
     --hash=sha256:4b90b09eeeb9b88c35bc642cbac057e45a5fd85367b985bd2809c62b7b939265 \
     --hash=sha256:e0d0eb91441a3b53dab4d9b743eafc1ac44476296a2053b6ca3af0b139faf87b