refactor: Use ServerlessError in poetry

Author: pgrzesik

lib/poetry.js

@@ -50,8 +50,9 @@ async function pyprojectTomlToRequirements() {
         e.stderrBuffer &&
         e.stderrBuffer.toString().includes('command not found')
       ) {
-        throw new Error(
-          `poetry not found! Install it according to the poetry docs.`
+        throw new this.serverless.classes.Error(
+          `poetry not found! Install it according to the poetry docs.`,
+          'PYTHON_REQUIREMENTS_POETRY_NOT_FOUND'
         );
       }
       throw e;