Added TravisCI.
Fixed installation of the package for Node v0.8 and similar.

In recent Node versions there is a 'finish' event on Writable stream ( http://nodejs.org/api/stream.html#stream_event_finish ), but there is no such event in 0.8. However, 'close' ( http://nodejs.org/docs/v0.8.6/api/stream.html#stream_event_close_1 ) apparently works for all versions.

Without listening on 'close', promise chain aborts on 'copyIntoPlace' without any notice, therefore following functions, such as 'fixFilePermissions', are never executed.

Fixes #9 and supersedes #10. Added TravisCI for testing of installation.
Merge branch 'honzajavorek-fix-installation'