Downgrade nightly for now to workaround pyo3 issue

PyO3/pyo3#614

README.md

@@ -32,15 +32,15 @@ First, see if a binary wheel is available for your machine by running:
 
 If that fails, install [rustup](https://rustup.rs) and then run:
 
-    $ rustup default nightly
+    $ rustup default nightly-2019-10-05
     $ pip install -U setuptools-rust
     $ pip install -U autopy
 
 Another option is to compile from the latest source on the GitHub repository:
 
     $ git clone git://github.com/autopilot-rs/autopy-rs.git
     $ cd autopy
-    $ rustup default nightly
+    $ rustup default nightly-2019-10-05
     $ pip install -r requirements.txt
     $ python setup.py build
     # python setup.py install

appveyor.yml

@@ -17,7 +17,7 @@ environment:
 # From https://github.com/starkat99/appveyor-rust/blob/master/appveyor.yml
 install:
   - appveyor DownloadFile https://win.rustup.rs/ -FileName rustup-init.exe
-  - rustup-init -yv --default-toolchain nightly --default-host %target%
+  - rustup-init -yv --default-toolchain nightly-2019-10-05 --default-host %target%
   - set PATH=%PATH%;%USERPROFILE%\.cargo\bin
   - rustc -vV
   - cargo -vV

scripts/travis

@@ -6,7 +6,7 @@ if [ ! -d ~/rust-installer ]; then
     set -x
     mkdir ~/rust-installer
     curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs -o ~/rust-installer/rustup.sh
-    sh ~/rust-installer/rustup.sh --default-toolchain=nightly -y
+    sh ~/rust-installer/rustup.sh --default-toolchain=nightly-2019-10-05 -y
     set +x
 fi