Delete code from master branch

The code for each post now lives in the `post-XX` branches where `XX` is the post number.

.travis.yml

@@ -1,17 +1,4 @@
-language: rust
-
-rust:
-    - nightly
-
-os:
-  - linux
-  - osx
-  - windows
-
-notifications:
-    email:
-        on_success: never
-        on_failure: always
+language: minimal
 
 branches:
   only:
@@ -24,29 +11,5 @@ branches:
     # Build post braches
     - /^post-.*$/
 
-cache:
-  directories:
-    - $HOME/.cargo
-    - $HOME/Library/Caches/Homebrew
-
-addons:
-  apt:
-    packages:
-      - qemu-system-x86
-  homebrew:
-    packages:
-      - qemu
-
-install:
-  - if [ $TRAVIS_OS_NAME = windows ]; then choco install qemu; export PATH="/c/Program Files/qemu:$PATH"; fi
-
-before_script:
-  - rustup component add rust-src
-  - (test -x $HOME/.cargo/bin/cargo-install-latest || cargo install cargo-install-latest)
-  - cargo install-latest cargo-xbuild bootimage cargo-cache
-
 script:
-  - bootimage build
-  - cargo test
-  - bootimage test
-  - cargo cache --autoclean
+  - echo "Nothing to do for master branch"