Export participants to different formats

* CSV
* PDF (requires Python dependency `weasyprint`)
* ODS (requires Python dependency `pyexcel_ods3`)

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

priv/python/module.py

@@ -0,0 +1,8 @@
+import pkg_resources
+
+def has_package(package):
+    try:
+        pkg_resources.get_distribution(package.decode('ascii'))
+        return True
+    except pkg_resources.DistributionNotFound:
+        return False