title: Allure-report empty when allure-results have multiple result folders
body: <p>The allure-results folders is in the following structure.</p>
  
  <pre><code>allure-results/
  |-- assertions1
  |   |-- 2f429779-3c86-4958-8e8b-e9a03a25cd20-attachment.txt
  |   |-- 312890b7-fd56-4c65-bee9-14d76ff4a58e-testsuite.xml
  |   |-- 3f385845-14cc-4411-86c2-06e35a76b2ad-attachment.txt
  |   |-- 59f04042-8f20-4c11-b611-b5364e892556-attachment.txt
  |   |-- 8829ef83-06d2-425d-b5c6-dc2e09b8b3b2-attachment.svg
  |   `-- e37938ed-0c9b-4ac4-99d5-0e80f240a79e-attachment.txt
  |-- assertions2
  |   |-- 0adb3f17-3e46-48e3-bdc9-9603b6d31084-attachment.txt
  |   |-- 0fd3980a-d55b-49b8-8bdd-c56b7282008d-attachment.txt
  |   |-- 20f132d1-8b4d-453c-9cea-53c7f59ff12e-attachment.svg
  |   |-- 2ed67517-f700-4cac-85f3-93aac1529828-attachment.txt
  |   |-- 45246942-4479-468a-bf29-72f2f19dfce9-testsuite.xml
  |   |-- 80b5e955-6cc3-4ce6-a954-ce46f554b810-attachment.txt
  |   |-- a01f2abf-52fa-47ff-99c0-a43a5bd0756b-attachment.txt
  |   |-- ce094c0b-256a-4bf6-92b3-17d2fadff3ca-attachment.txt
  |   |-- e95eedf9-0d8f-49d6-8fd6-c02d4e1181bd-attachment.txt
  |   `-- f7891f5d-e115-4031-a56a-203bb2f73d38-attachment.txt
  |-- environment.xml
  |-- assertions3
  |   |-- c052da82-213b-4db2-8a33-7e96e501907c-testsuite.xml
  |   `-- fd72c264-f037-4a02-b797-5407dd50a297-attachment.txt
  |-- assertions4
  |   |-- 8d8df3dd-47e1-416e-acb7-6ef62d529c0f-attachment.txt
  |   `-- c2dadf11-fcbc-4027-97bc-98849be24540-testsuite.xml
  |-- assertions5
  |   |-- ea11687b-7846-4bbb-923c-8cc62f7c69b5-attachment.txt
  |   `-- f24ddf31-a3f8-4feb-bf07-ba6465ee4555-testsuite.xml
  `-- assertions6
      |-- 08d24268-a755-4969-aa3b-5660951fd21d-testsuite.xml
      `-- 6b4590bf-4df7-4e39-941e-63e1f902968a-attachment.txt
  </code></pre>
  
  <p>We can see that there are multiple testsuite results in it along with environment.xml.</p>
  
  <p>I am trying to generate an allure report for it. Latest allurecommandline is installed.</p>
  
  <p>When I try to run the following command, the allure report is empty.</p>
  
  <p><code>allure generate allure-results/</code></p>
  
  <p>It works when I give an individual result directory.</p>
  
  <p><code>allure generate allure-results/assertions1</code></p>
  
  <p>I am looking for a way to make allure generate a report based on all the testsuite results folders present in the allure-results.</p>
  
  <p>The testsuite results are generated using python nosetests.</p>