Addressing @adamrp's comments

Author: josenavas

qiita_db/metadata_template/test/test_util.py

@@ -239,9 +239,8 @@ def test_looks_like_qiime_mapping_file(self):
             StringIO(QIIME_TUTORIAL_MAP_SUBSET))
         self.assertTrue(obs)
 
-    def test_looks_like_qiime_mmapping_file_error(self):
-        with self.assertRaises(QiitaDBError):
-            looks_like_qiime_mapping_file(StringIO())
+        obs = looks_like_qiime_mapping_file(StringIO())
+        self.assertFalse(obs)
 
     def test_parse_mapping_file(self):
         # Tests ported over from QIIME

qiita_db/metadata_template/util.py

@@ -346,10 +346,6 @@ def looks_like_qiime_mapping_file(fp):
     bool
         True if fp looks like a QIIME mapping file, false otherwise.
 
-    Raises
-    ------
-    QiitaDBError
-        If an empty file is passed
 
     Notes
     -----
@@ -362,7 +358,7 @@ def looks_like_qiime_mapping_file(fp):
     with open_file(fp, mode='U') as f:
         first_line = f.readline()
     if not first_line:
-        raise QiitaDBError('Empty file passed!')
+        return False
 
     first_col = first_line.split()[0]
     return first_col == '#SampleID'