Update copyright notice & disclaimer to reflect current year (2019)

Copyright notice in mUzima mobile projects needs to be updated to reflect the current year. There are two possible ways in which this could be done:

1. Update the notice so that it does not include the year (Similar to OpenMRS projects, e.g this in mUzimaCore) so that we do not have to update the copyright notice every year.
2. Update the year as usually done.