Add a new Google Sheet loader

Author: stloyd

src/adapter/etl-adapter-google-sheet/.gitignore

@@ -1,3 +1,4 @@
 vendor
 *.cache
-var
+var
+auth.json.dist

src/adapter/etl-adapter-google-sheet/tests/Flow/ETL/Adapter/GoogleSheet/Tests/Integration/GoogleSheetTest.php

@@ -25,17 +25,18 @@ protected function setUp() : void
     {
         parent::setUp();
 
-        if (!isset($_ENV['GOOGLE_SHEETS_AUTH'])) {
-            self::markTestSkipped('GOOGLE_SHEETS_AUTH environment variable is not set');
+        $authFilename = __DIR__ . '/../../../../../../../auth.json.dist';
+        if (!file_exists($authFilename)) {
+            self::markTestSkipped('auth.json.dist file is missing');
         }
 
         try {
             $this->service = google_sheets(
-                json_decode((string) $_ENV['GOOGLE_SHEETS_AUTH'], true, 512, JSON_THROW_ON_ERROR),
+                json_decode((string) file_get_contents($authFilename), true, 512, JSON_THROW_ON_ERROR),
                 Sheets::SPREADSHEETS
             );
         } catch (\JsonException) {
-            self::markTestSkipped('GOOGLE_SHEETS_AUTH environment variable is not valid JSON');
+            self::markTestSkipped('auth.json.dist file contains not valid JSON');
         }
 
         $this->spreadsheetId = google_create_spreadsheet(