Enable x86_64-linux-android travis build

.travis.yml

@@ -91,6 +91,10 @@ matrix:
       env: TARGET=i686-linux-android
            DOCKER=android
            SKIP_TESTS=1
+    - os: linux
+      env: TARGET=x86_64-linux-android
+           DOCKER=android
+           SKIP_TESTS=1
 
     # On OSX we want to target 10.7 so we ensure that the appropriate
     # environment variable is set to tell the linker what we want.
@@ -122,7 +126,7 @@ install:
   - sudo pip install awscli
   - aws configure set preview.cloudfront true
   - curl https://static.rust-lang.org/rustup.sh |
-    sh -s -- --prefix=$HOME/rust --spec=nightly-2016-11-06 --with-target=$TARGET
+    sh -s -- --prefix=$HOME/rust --spec=nightly-2017-04-25 --with-target=$TARGET
 
 script:
   - mkdir -p target/$TARGET

README.md

@@ -532,6 +532,7 @@ platform of your choice:
 - [i686-linux-android](https://static.rust-lang.org/rustup/dist/i686-linux-android/rustup-init)
 - [i686-unknown-linux-gnu](https://static.rust-lang.org/rustup/dist/i686-unknown-linux-gnu/rustup-init)
 - [x86_64-apple-darwin](https://static.rust-lang.org/rustup/dist/x86_64-apple-darwin/rustup-init)
+- [x86_64-linux-android](https://static.rust-lang.org/rustup/dist/x86_64-linux-android/rustup-init)
 - [x86_64-pc-windows-gnu](https://static.rust-lang.org/rustup/dist/x86_64-pc-windows-gnu/rustup-init.exe)
 - [x86_64-pc-windows-msvc](https://static.rust-lang.org/rustup/dist/x86_64-pc-windows-msvc/rustup-init.exe)<sup>[†](#vs2015)</sup>
 - [x86_64-unknown-freebsd](https://static.rust-lang.org/rustup/dist/x86_64-unknown-freebsd/rustup-init)

appveyor.yml

@@ -44,7 +44,7 @@ install:
 
   # Install rust, x86_64-pc-windows-msvc host
   - appveyor DownloadFile https://win.rustup.rs/ -FileName rustup-init.exe
-  - rustup-init.exe -y --default-toolchain=nightly-2017-01-06-x86_64-pc-windows-msvc
+  - rustup-init.exe -y --default-toolchain=nightly-2017-04-25-x86_64-pc-windows-msvc
   - set PATH=%PATH%;C:\Users\appveyor\.cargo\bin
 
   # Install the target we're compiling for