travis: build the examples too

[bagder]

to make sure they keep building warning-free

[coveralls]

Coverage decreased (-0.03%) to 75.063% when pulling 4174dec on bagder/travis-examples into adc35a4 on master.

[MarcelRaad]

Isn't --enable-werror only for the library and tool? IIRC, the examples and tests always build without warnings-as-errors. But keeping them building at all is an improvement too of course :-)

[bagder]

Yes, I'm mostly concerned that they build at all, I'm not at all convinced that --werror is a good idea for the examples.

[MarcelRaad]

Ah, I misread the description to mean that. Yes, warnings-as-errors doesn't even work on Windows without complicating the examples because some WinSock function parameter is unsigned int when it should be size_t.

[bagder]

Thanks for the review @MarcelRaad