Updated CI config to reflect deprecation of rustup uninstall

Author: Markus Pettersson

.appveyor.yml

@@ -27,7 +27,7 @@ install:
     - rustup-init.exe -y --default-host %TARGET% --default-toolchain stable --profile minimal
     - set PATH=%USERPROFILE%\.cargo\bin;%PATH%
     - rustup default stable
-    - rustup uninstall beta
+    - rustup toolchain uninstall beta
     - rustup update
     # Install "master" toolchain
     - cargo install rustup-toolchain-install-master & exit 0

.travis.yml

@@ -34,7 +34,7 @@ before_script:
 - curl https://build.travis-ci.org/files/rustup-init.sh -sSf | sh -s -- -y --default-toolchain stable --profile minimal
 - export PATH=$HOME/.cargo/bin:$PATH
 - rustup default stable
-- rustup uninstall beta
+- rustup toolchain uninstall beta
 - rustup update
 # Install "master" toolchain
 - cargo install rustup-toolchain-install-master || echo "rustup-toolchain-install-master already installed"