Make example code better describe its failure for newbies

[overfl0]

The current code for querying the master server in README.md assumes only the master server can timeout, which makes people think something is wrong with the master server (or the library), while iterating over game servers (many of which will be unreachable for some reason).

An example of an issue caused by this lack of error checking here: #63

Changes:

• Use a separate try/except per server for timeout detection.
• Use python3 print everywhere.

Note: I have just modified the README.md file. The Travis checks were already failing previously.

[coveralls]

Coverage increased (+0.09%) to 70.24% when pulling 24c68dd9cff125ec5cbaabb5646e12dff96cb816 on overfl0:fix_readme into 526bb0e1848567e55b3d6ce900cc76b5394a5ca6 on serverstf:master.

[Yepoleb]

Good idea, thanks for your contribution!