Run rustfmt on sr.ht

This should provide more clear feedback whether rustfmt
job is failed or not.

.builds/rustfmt.yml

@@ -0,0 +1,10 @@
+image: archlinux
+sources:
+  - https://github.com/alacritty/alacritty
+tasks:
+  - rustup: |
+      curl https://sh.rustup.rs -sSf | sh -s -- -y --default-toolchain nightly --profile minimal
+      $HOME/.cargo/bin/rustup component add rustfmt
+  - rustfmt: |
+      cd alacritty
+      $HOME/.cargo/bin/cargo fmt -- --check

.travis.yml

@@ -36,10 +36,6 @@ matrix:
       os: windows
       env: CLIPPY=true
       rust: 1.41.0-x86_64-pc-windows-msvc
-    - name: "Rustfmt"
-      os: linux
-      env: RUSTFMT=true
-      rust: nightly
     - name: "Windows 1.41.0"
       os: windows
       rust: 1.41.0-x86_64-pc-windows-msvc

ci/install.sh

@@ -4,8 +4,3 @@
 if [ "$CLIPPY" == "true" ]; then
     rustup component add clippy
 fi
-
-# Add rustfmt for format validation
-if [ "$RUSTFMT" == "true" ]; then
-    rustup component add rustfmt
-fi

ci/script.sh

@@ -6,12 +6,6 @@ if [ "$CLIPPY" == "true" ]; then
     exit
 fi
 
-# Run clippy rustfmt
-if [ "$RUSTFMT" == "true" ]; then
-    cargo fmt -- --check
-    exit
-fi
-
 # Run test in release mode if a tag is present, to produce an optimized binary
 if [ -n "$TRAVIS_TAG" ]; then
     # Build separately so we generate an 'alacritty' binary without -HASH appended