[bug] Fix CSV upload feature for DB with password (apache#4562)

* Use sqlalchemy_uri_decrypted in create_engine calls

* Update tox mysql uri

* Include mysql charset=utf8 for py2.7 in tox.ini

superset/db_engine_specs.py

@@ -135,7 +135,7 @@ def _allowed_file(filename):
             'table': table,
             'df': df,
             'name': form.name.data,
-            'con': create_engine(form.con.data.sqlalchemy_uri, echo=False),
+            'con': create_engine(form.con.data.sqlalchemy_uri_decrypted, echo=False),
             'schema': form.schema.data,
             'if_exists': form.if_exists.data,
             'index': form.index.data,
@@ -875,7 +875,7 @@ def get_column_names(filepath):
             TEXTFILE LOCATION '{location}'
             tblproperties ('skip.header.line.count'='1')""".format(**locals())
         logging.info(form.con.data)
-        engine = create_engine(form.con.data.sqlalchemy_uri)
+        engine = create_engine(form.con.data.sqlalchemy_uri_decrypted)
         engine.execute(sql)
 
     @classmethod

tox.ini

@@ -82,7 +82,7 @@ commands =
 [testenv:py27-mysql]
 basepython = python2.7
 setenv =
-    SUPERSET__SQLALCHEMY_DATABASE_URI = mysql://root@localhost/superset?charset=utf8
+    SUPERSET__SQLALCHEMY_DATABASE_URI = mysql://mysqluser:mysqluserpassword@localhost/superset?charset=utf8
 
 [testenv:py34-mysql]
 basepython = python3.4