Add checksum control od db download and switch to urllib3

utilities.py

@@ -0,0 +1,18 @@
+import hashlib
+from pandas import read_csv
+
+def checksum_ok(data, what):
+    code = hashlib.sha256()
+    code.update(data)
+    ref_loc = 'https://aresvalley.com/Storage/Artemis/Database/data.zip.log'
+    if what == "folder":
+        n = 0
+    elif what == "db":
+        n = 1
+    else:
+        raise ValueError("Wrong entry name.")
+    try:
+        reference = read_csv(ref_loc, delimiter = '*').iat[-1, n]
+    except HTTPError:
+        return False
+    return code.hexdigest() == reference