Upgrade to Rust 1.31.0 (#2052)

* Upgrade to Rust 1.31.0
* Upgrade nightly
* Fix all clippy warnings
* Revert relaxed version check and update

ci/buildkite.yml

@@ -2,7 +2,7 @@ steps:
   - command: "ci/shellcheck.sh"
     name: "shellcheck [public]"
     timeout_in_minutes: 20
-  - command: "ci/docker-run.sh solanalabs/rust:1.30.1 ci/test-checks.sh"
+  - command: "ci/docker-run.sh solanalabs/rust:1.31.0 ci/test-checks.sh"
     name: "checks [public]"
     env:
       CARGO_TARGET_CACHE_NAME: "checks"
@@ -20,12 +20,12 @@ steps:
     env:
       CARGO_TARGET_CACHE_NAME: "nightly"
     timeout_in_minutes: 30
-  - command: "ci/docker-run.sh solanalabs/rust:1.30.1 ci/test-stable.sh"
+  - command: "ci/docker-run.sh solanalabs/rust:1.31.0 ci/test-stable.sh"
     name: "stable [public]"
     env:
       CARGO_TARGET_CACHE_NAME: "stable"
     timeout_in_minutes: 30
-  - command: "ci/docker-run.sh solanalabs/rust-nightly:2018-11-12 ci/test-nightly.sh"
+  - command: "ci/docker-run.sh solanalabs/rust-nightly:2018-12-05 ci/test-nightly.sh"
     name: "nightly [public]"
     env:
       CARGO_TARGET_CACHE_NAME: "nightly"

ci/docker-rust/Dockerfile

@@ -1,6 +1,6 @@
 # Note: when the rust version is changed also modify
 # ci/buildkite.yml to pick up the new image tag
-FROM rust:1.30.1
+FROM rust:1.31.0
 
 RUN set -x && \
     apt update && \
@@ -20,8 +20,8 @@ RUN set -x && \
       rsync \
       sudo \
       && \
-    rustup component add rustfmt-preview && \
-    rustup component add clippy-preview && \
+    rustup component add rustfmt && \
+    rustup component add clippy && \
     rm -rf /var/lib/apt/lists/* && \
     rustc --version && \
     cargo --version

ci/version-check.sh

@@ -24,8 +24,8 @@ nightly)
   require cargo 1.32.[0-9]+-nightly
   ;;
 stable)
-  require rustc 1.3[01].[0-9]+
-  require cargo 1.3[01].[0-9]+
+  require rustc 1.31.[0-9]+
+  require cargo 1.31.[0-9]+
   ;;
 *)
   echo Error: unknown argument: "$1"