CI improvements about pagmo2

[darioizzo]

• automatically upload documentation to gh-pages ?

• manylinux builds and automated upload to PyPi ?

[darioizzo]

• run make doctest in some CI? (maybe in the compile script)

[darioizzo]

Would it be posible (desirable) to eliminate the test output from the travis CI logs? Its very long and the logs cannot exceed 10000 lines. Eventually it will saturate (we are at ~7000) ...

[bluescarni]

@darioizzo I suspect it will be enough to just drop -V from the ctest invocation. I'll look into it.

[bluescarni]

CI verbosity should be fixed in #21.

[bluescarni]

This should all be done, with the exception of the 32 bit builds that we agreed not to pursue for the moment. Closing.