Fix #287: Broken quoted section name starts with dot (#330)

toml/decoder.py

diff --git a/toml/decoder.py b/toml/decoder.py
index c8ea681..bf400e9 100644
--- a/toml/decoder.py
+++ b/toml/decoder.py
@@ -440,7 +440,8 @@
                                            groups[i][0] == "'"):
                     groupstr = groups[i]
                     j = i + 1
-                    while not groupstr[0] == groupstr[-1]:
+                    while ((not groupstr[0] == groupstr[-1]) or
+                           len(groupstr) == 1):
                         j += 1
                         if j > len(groups) + 2:
                             raise TomlDecodeError("Invalid group name '" +