Fix link error on PyPy+Linux

Author: dahlia

.travis.yml

@@ -6,7 +6,7 @@ python:
 - 2.5
 - 2.6
 - 2.7
-#- pypy
+- pypy
 install:
 - pip install Attest
 script:

setup.py

@@ -55,7 +55,7 @@ def spawn(self, cmd):
     macros = {'LIBSASS_PYTHON_VERSION': '\\"' + version + '\\"'}
 else:
     flags = ['-fPIC', '-Wall', '-Wno-parentheses', '-Wno-tautological-compare']
-    link_flags = ['-fPIC']
+    link_flags = ['-fPIC', '-lstdc++']
     macros = {'LIBSASS_PYTHON_VERSION': '"' + version + '"'}
 
 sass_extension = Extension(