Use certifi for more portable TLS cert validation

main.py

@@ -17,6 +17,7 @@ import urllib3
 from msgpack import dumps
 import psutil
 import posix1e  # pylibacl
+import certifi
 
 
 def compute_hashes(entry_path):
@@ -150,7 +151,8 @@ def construct_fs_tree(mp_pool=None, mp_tasks=[], cur_dict=None, path="/", dev_wh
 
 
 def upload_to_erp5(fileobj, size, base_url, username, password, reference):
-    pool = urllib3.PoolManager()
+    pool = urllib3.PoolManager(cert_reqs='CERT_REQUIRED',
+                               ca_certs=certifi.where())
 
     url = '{0}/portal_contributions/newContent'.format(base_url)
     headers = urllib3.make_headers(