bug: assert.rejects returns a rejected Promise

that means that we have to wait for the failure to
fully resolve to not propagate down the rest of the
test suite.

Author: gnikit

test/unitTest/tools.test.ts

@@ -16,7 +16,7 @@ suite('Tools tests', () => {
 
   test('shellTask returns rejected promise', async () => {
     const name = 'pip: fortls';
-    assert.rejects(shellTask('python3', ['-m', 'pip', 'install', 'fortls2'], name));
+    await assert.rejects(shellTask('python3', ['-m', 'pip', 'install', 'fortls2'], name));
   });
 
   test('spawnAsPromise correct stdout, stderr output exit code 0', async () => {