Merge branch 'release/v0.6.0' into develop
enable travis ci support
add travis-ci badge to readme.md

visualise travis state
use default task as test task for 'npm test' script

this seems more simple
add fix + example for duplicate msgid problem

those two cases will produce invalid pot files if parsed as is. Extract
will throw an exception, now.
Merge branch 'fix_duplicate_msgids' into develop
cleanup output of exception

the item indeed is a po item and has references. The old behaviour was
tailored to an older implementation of the fix.
fix the duplicate msgid detection fix

there has been an edge case, that has been taken care of, now.
bump version to 0.6.1
Merge branch 'release/v0.6.1'