Remove Travis configuration

.github/workflows/ci.yml

@@ -1,4 +1,4 @@
-name: test
+name: CI
 
 on:
   push:

.travis.yml

@@ -1,24 +0,0 @@
-language: rust
-
-rust:
-  - beta
-  - stable
-  - 1.36.0
-
-script: cargo test --all
-
-matrix:
-  include:
-    - rust: nightly
-      env: RUSTFLAGS='--cfg thiserror_nightly_testing'
-    - rust: 1.31.0
-      script: cargo check
-    - name: Clippy
-      install:
-        - CLIPPY_NIGHTLY=nightly-$(curl -s https://rust-lang.github.io/rustup-components-history/x86_64-unknown-linux-gnu/clippy)
-        - echo "Latest nightly with Clippy is $CLIPPY_NIGHTLY"
-        - rustup set profile minimal
-        - rustup default "$CLIPPY_NIGHTLY"
-        - rustup component add clippy
-      script:
-        - cargo clippy --all -- -Dclippy::all