Update rust toolchain for now

.github/workflows/python-release.yml

@@ -76,7 +76,7 @@ jobs:
       - name: Install Rust
         uses: actions-rs/toolchain@v1
         with:
-          toolchain: nightly
+          toolchain: nightly-2020-05-18
           override: true
 
       - name: Install Python

bindings/python/build-wheels.sh

@@ -1,7 +1,7 @@
 #!/bin/bash
 set -ex
 
-curl https://sh.rustup.rs -sSf | sh -s -- --default-toolchain nightly-2019-11-01 -y
+curl https://sh.rustup.rs -sSf | sh -s -- --default-toolchain nightly-2020-05-18 -y
 export PATH="$HOME/.cargo/bin:$PATH"
 
 for PYBIN in /opt/python/{cp35-cp35m,cp36-cp36m,cp37-cp37m,cp38-cp38}/bin; do

bindings/python/rust-toolchain

@@ -1 +1 @@
-nightly
+nightly-2020-05-18