Making sure that in target gene studies, the QIIME required columns are on the prep template
Modifying test commands to reflect the latest changes on PrepTemplate requirements
Adding a specific test for the ValueError
Generating minimal QIIME-compliant mapping file for split libraries
Modifying populate_test_db.sql so it has all the required columns for target gene studies
Adding tests for the minimal QIIME-compliant mapping generation
Removing Description as a required column on the prep template
Adressing @ElDeveloper's comments
Addressing comments
writing out sample_name in MetadataTemplate.to_file instead of SampleID
Merge pull request #389 from josenavas/prep_req_columns

Add required PrepTemplate columns for target gene studies