Add 1.34.2, beta, nightly to travis

.travis.yml

@@ -1,16 +1,38 @@
 language: "rust"
 cache: "cargo"
+rust:
+  - 1.34.2
+  - stable
+  - beta
+  - nightly
+jobs:
+  allow_failures:
+    - rust: nightly
+  fast_finish: true
+
 before_script:
-  - "rustup component add rustfmt"
-  - "rustup component add clippy"
-  - "cargo install --force cargo-audit"
-  - "cargo generate-lockfile"
+  - rustup component add rustfmt
+  - |
+      if [ "$TRAVIS_RUST_VERSION" != "1.34.2" ]; then
+        rustup component add clippy
+      fi
+  - |
+      if [ "$TRAVIS_RUST_VERSION" == "stable" ]; then
+        cargo install --force cargo-audit
+      fi
+  - cargo generate-lockfile
 script:
-  - "cargo audit"
-  - "cargo fmt --all -- --check"
-  - "cargo clippy --all-targets --all-features -- -D warnings"
-  - "cargo build --verbose"
-  - "cargo test --verbose"
+  - |
+      if [ "$TRAVIS_RUST_VERSION" == "stable" ]; then
+        cargo audit
+      fi
+  - cargo fmt -- --check
+  - |
+      if [ "$TRAVIS_RUST_VERSION" != "1.34.2" ]; then
+        cargo clippy --all-targets --all-features -- -D warnings
+      fi
+  - cargo build --verbose
+  - cargo test --verbose
 if: "type != push OR (tag IS blank AND branch = master)"
 notifications:
   email: false

README.md

@@ -6,7 +6,7 @@
 
 ## Minimum Rust version
 
-ruma-identifiers requires Rust 1.34 or later.
+ruma-identifiers requires Rust 1.34.2 or later.
 
 ## Documentation