/notes has optional start and end dates
return 400 invalid dates, dates exclusive
beef up date range tests

400 on invalid date
test when only endtime is specified
my bad
add check for param to getDateFromParam
Merge pull request #15 from tidepool-org/jhbate/notes-daterange

/notes has optional start and end dates
Merge branch 'master' into jhbate/fix-message-author