cleanup: remove leftover rust-docs components

.appveyor.yml

@@ -25,6 +25,7 @@ install:
     - set PATH=%USERPROFILE%\.cargo\bin;%PATH%
     - rustup default stable
     - rustup uninstall beta
+    - rustup component remove rust-docs & exit 0
     - rustup update
     # Install "master" toolchain
     - cargo install rustup-toolchain-install-master & exit 0

.travis.yml

@@ -35,6 +35,7 @@ before_script:
 - export PATH=$HOME/.cargo/bin:$PATH
 - rustup default stable
 - rustup uninstall beta
+- rustup component remove rust-docs || echo "rust-docs already gone"
 - rustup update
 # Install "master" toolchain
 - cargo install rustup-toolchain-install-master || echo "rustup-toolchain-install-master already installed"