drop run_rust_emacs_tests.sh and use make test in ci

Author: brotzeit

.github/workflows/test.yml

@@ -28,5 +28,7 @@ jobs:
         version: ${{ matrix.emacs_version }}
 
     - uses: actions/checkout@v1
+
     - name: Run tests
-      run: './run_rust_emacs_tests.sh'
+      run: |
+        make test

README.md

@@ -149,15 +149,16 @@ mode for integration with Cargo, Rust's package manager.
 [cargo-mode](https://github.com/ayrat555/cargo-mode) is an Emacs minor mode which allows to dynamically select a Cargo command. The reasons behind this package can be found in [the post](https://www.badykov.com/emacs/2021/05/29/emacs-cargo-mode/).
 
 ## Rustic
-[rustic](https://github.com/brotzeit/rustic) is a fork of rust-mode,
+[rustic](https://github.com/brotzeit/rustic) is based on rust-mode,
 extending it with other features such as integration with LSP and with flycheck.
 
 
 # For package maintainers
 
 ## Tests
 
-The file `rust-mode-tests.el` contains tests that can be run via
-[ERT](http://www.gnu.org/software/emacs/manual/html_node/ert/index.html).
-You can use `run_rust_emacs_tests.sh` to run them in batch mode, if
-you set the environment variable EMACS to a program that runs emacs.
+Run elisp tests:
+
+``` bash
+make test
+```