Add compiled modules sources + readme

extensions/README.rst

@@ -0,0 +1,10 @@
+This directory contains extensions modules pre-compiled to be tested
+on Travis-CI (Ubuntu 12.04 64bit).
+
+To build the extensions modules, run::
+
+    python setup.py build_ext -i
+
+
+Then move the compiled modules to their testing package ( ./**compiledXX**, where XX is the
+python version used to run setup.py).

extensions/compiled.pyx

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+cdef class Foo:
+    pass
+
+
+cdef class Bar:
+    pass

extensions/setup.py

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+from distutils.core import setup
+from Cython.Build import cythonize
+
+setup(
+    ext_modules=cythonize("compiled.pyx")
+)