Fix #204 triple quote detection incorrect on non stripped line

triple quote """ or ''' ending a multiline string are not checked
correctly if line ends with comments or spacing or anything

tests/test_api.py

@@ -270,3 +270,15 @@ def test_comment_preserve_decoder_encoder():
                    encoder=toml.TomlPreserveCommentEncoder())
 
     assert len(s) == len(test_str) and sorted(test_str) == sorted(s)
+
+
+@pytest.mark.xfail
+def test_checks_on_triple_quote_fail():
+    assert toml.loads('foo="""1\\\n2"""# toto ')['foo'] == "1\\\n2"
+
+
+def test_checks_on_triple_quote():
+    assert toml.loads('foo="""1\n2"""# toto ')['foo'] == "1\n2"
+    assert toml.loads('foo="""1\n2\n"""# toto ')['foo'] == "1\n2\n"
+    assert toml.loads('foo=["""1\n2"""]# toto ')['foo'] == ["1\n2"]
+    assert toml.loads('foo=["""1\n2"""# toto\n]# toto')['foo'] == ["1\n2"]

toml/decoder.py

@@ -375,18 +375,19 @@ def loads(s, _dict=dict, decoder=None):
         if line == "" and (not multikey or multibackslash):
             continue
         if multikey:
+            closed = False
+            line_clean_end = line.rstrip()
+            if multilinestr[0] == '[':
+                closed = line_clean_end[-1] == ']'
+            elif len(line) > 2:
+                closed = line_clean_end[-3:] == multilinestr[:3]
+            if closed:
+                line = line_clean_end
             if multibackslash:
                 multilinestr += line
             else:
                 multilinestr += line
             multibackslash = False
-            closed = False
-            if multilinestr[0] == '[':
-                closed = line[-1] == ']'
-            elif len(line) > 2:
-                closed = (line[-1] == multilinestr[0] and
-                          line[-2] == multilinestr[0] and
-                          line[-3] == multilinestr[0])
             if closed:
                 try:
                     value, vtype = decoder.load_value(multilinestr)