travis: switch to rustfmt-preview for style checks

.travis.yml

@@ -11,7 +11,6 @@ env:
     - RUSTFLAGS=-Dwarnings
     # Versions known to work with pinned nightly.
     - CLIPPY_VERSION=0.0.180
-    - RUSTFMT_VERSION=0.3.6
 
 before_script:
   - export PATH=$HOME/.cargo/bin:$PATH
@@ -23,12 +22,12 @@ before_script:
     fi
   - |
     if [[  $TRAVIS_RUST_VERSION =~ nightly-* ]]; then
+        rustup component add rustfmt-preview
         cargo install-update -i "clippy:$CLIPPY_VERSION"
-        cargo install-update -i "rustfmt-nightly:$RUSTFMT_VERSION"
     fi
 script:
-  - cargo build && cargo test
   - |
     [[ ! $TRAVIS_RUST_VERSION =~ nightly-* ]] || cargo fmt -- --write-mode diff
+  - cargo build && cargo test
   - |
     [[ ! $TRAVIS_RUST_VERSION =~ nightly-* ]] || cargo clippy

src/cli.rs

@@ -70,7 +70,8 @@ pub enum Crater {
         env: DockerEnv,
     },
 
-    #[structopt(name = "create-lists", about = "create all the lists of crates")] CreateLists,
+    #[structopt(name = "create-lists", about = "create all the lists of crates")]
+    CreateLists,
 
     #[structopt(name = "define-ex", about = "define an experiment")]
     DefineEx {
@@ -107,10 +108,7 @@ pub enum Crater {
     },
 
     #[structopt(name = "copy-ex", about = "copy all data from one experiment to another")]
-    CopyEx {
-        ex1: Ex,
-        ex2: Ex,
-    },
+    CopyEx { ex1: Ex, ex2: Ex },
 
     #[structopt(name = "delete-ex", about = "delete shared data for experiment")]
     DeleteEx {
@@ -174,7 +172,8 @@ pub enum Crater {
         s3_prefix: Option<report::S3Prefix>,
     },
 
-    #[structopt(name = "serve-report", about = "serve report")] Serve,
+    #[structopt(name = "serve-report", about = "serve report")]
+    Serve,
 }
 
 impl Crater {