Coverge improvements (#22)

* Update cli.py

* improved tests

* chnages for proper testing

* Type check using isinstance

* Replace elifs with if when used after return

* twitter.com --> www.ibm.com

* fix typo

* test archive urll parser and dunders

* Update test_wrapper.py

tests/test_wrapper.py

@@ -23,6 +23,21 @@ def test_clean_url():
     test_result = target._clean_url()
     assert answer == test_result
 
+def test_dunders():
+    url = "https://en.wikipedia.org/wiki/Network_security"
+    user_agent = "UA"
+    target = waybackpy.Url(url, user_agent)
+    assert "waybackpy.Url(url=%s, user_agent=%s)" % (url, user_agent) == repr(target)
+    assert len(target) == len(url)
+    assert str(target) == url
+
+def test_archive_url_parser():
+    request_url = "https://amazon.com"
+    hdr = {"User-Agent": user_agent}  # nosec
+    req = Request(request_url, headers=hdr)  # nosec
+    header = waybackpy._get_response(req).headers
+    with pytest.raises(Exception):
+        waybackpy._archive_url_parser(header)
 
 def test_url_check():
     broken_url = "http://wwwgooglecom/"
@@ -40,7 +55,7 @@ def test_save():
         "commons.wikimedia.org",
         "www.wiktionary.org",
         "www.w3schools.com",
-        "twitter.com",
+        "www.ibm.com",
     ]
     x = random.randint(0, len(url_list) - 1)
     url1 = url_list[x]