Make CI use PyTorch nightly (#1492)

Author: fmassa

.circleci/config.yml

@@ -39,9 +39,9 @@ binary_common: &binary_common
       type: string
       default: ""
     pytorch_version:
-      description: "PyTorch version to build against; by default, use 1.3. Use empty string for nightly"
+      description: "PyTorch version to build against; by default, use a nightly"
       type: string
-      default: "1.3"
+      default: ""
     # Don't edit these
     python_version:
       description: "Python version to build against (e.g., 3.7)"

.circleci/config.yml.in

@@ -39,9 +39,9 @@ binary_common: &binary_common
       type: string
       default: ""
     pytorch_version:
-      description: "PyTorch version to build against; by default, use 1.3. Use empty string for nightly"
+      description: "PyTorch version to build against; by default, use a nightly"
       type: string
-      default: "1.3"
+      default: ""
     # Don't edit these
     python_version:
       description: "Python version to build against (e.g., 3.7)"

.travis.yml

@@ -42,7 +42,7 @@ before_install:
   # Useful for debugging any issues with conda
   - conda info -a
 
-  - conda create -q -n test-environment python=$TRAVIS_PYTHON_VERSION pytorch scipy -c pytorch
+  - conda create -q -n test-environment python=$TRAVIS_PYTHON_VERSION pytorch scipy -c pytorch-nightly
   - source activate test-environment
   - |
     if [[ "$IMAGE_BACKEND" == "Pillow-SIMD" ]]; then