Added test for writing the log

tests/test_log.py

@@ -0,0 +1,10 @@
+from src import config
+
+
+def test_write_to_log():
+    conf = config.read_config(r'config.yaml')
+    log_file = conf['General']['log_file']
+    text = '2021/03/08 23:24:52 17931875 bb3 [INFO Client 1492] @From Sinusal: Hi, I would like to buy your level 21 23% Vaal Impurity of Lightning ' \
+        'listed for 18 chaos in Ritual (stash tab "$"; position: left 22, top 5)'
+    with open(log_file, 'a') as f:
+        f.write(text)