fixing twitter button
adding new function: adherence calculator version three
fixed adherence calculator for migrated data
added new script to fix migrated data
added function to script to fix retired drugs used in drug orders
added exception for missing date of birth
adding new concepts
Merge branch 'adherence_calculation' of github.com:BaobabHealthTrust/bart2 into adherence_calculation
Merge branch 'adherence_calculation'
Merge branch 'master' of github.com:BaobabHealthTrust/bart2