ci: remove source code with script

Remove connector source code for pure install tests with Python script.
Python was chosen since it would work both on Windows and Linux.

Part of #198

Author: DifferentialOrange

Diff for: .github/scripts/remove_source_code.py

@@ -0,0 +1,14 @@
+import os, shutil
+
+required_paths = ['.git', '.github', 'test', 'requirements-test.txt']
+
+for path in os.listdir():
+    if path in required_paths:
+        continue
+
+    if os.path.isfile(path) or os.path.islink(path):
+        os.remove(path)
+    elif os.path.isdir(path):
+        shutil.rmtree(path)
+    else:
+        raise ValueError(f"{path} is not a file, link or dir")

Diff for: .github/workflows/testing.yml

@@ -176,9 +176,7 @@ jobs:
         uses: actions/checkout@v2
 
       - name: Remove connector source code
-        run: |
-          rm -rf tarantool
-          rm setup.py
+        run: python .github/scripts/remove_source_code.py
 
       - name: Install tarantool ${{ matrix.tarantool }}
         uses: tarantool/setup-tarantool@v1
@@ -306,15 +304,8 @@ jobs:
       - name: Clone the connector repo
         uses: actions/checkout@v2
 
-      - name: Remove connector source code (main folder)
-        uses: JesseTG/[email protected]
-        with:
-          path: tarantool
-
-      - name: Remove connector source code (setup.py)
-        uses: JesseTG/[email protected]
-        with:
-          path: setup.py
+      - name: Remove connector source code
+        run: python .github/scripts/remove_source_code.py
 
       - name: Setup Python for tests
         uses: actions/setup-python@v2