Adds a test for logo validation

Added tests for new logo validation behaviour which
restricts  file type of the logo image uploaded.
Also fix i18 import in package_base.py

Closes-Bug: #1497257
Related-Bug: #1560547
Change-Id: I772e4b1fc56de86171938a536197b253a131645c

murano/packages/package_base.py

@@ -22,6 +22,7 @@ import sys
 import semantic_version
 import six
 
+from murano.common.i18n import _
 from murano.packages import exceptions
 from murano.packages import package
 

murano/tests/unit/api/v1/test_catalog.py

@@ -27,12 +27,14 @@ from six.moves import range
 from murano.api.v1 import catalog
 from murano.db.catalog import api as db_catalog_api
 from murano.db import models
+from murano.packages import exceptions
 from murano.packages import load_utils
 import murano.tests.unit.api.base as test_base
 import murano.tests.unit.utils as test_utils
 
 
 class TestCatalogApi(test_base.ControllerTest, test_base.MuranoApiTestCase):
+
     def setUp(self):
         super(TestCatalogApi, self).setUp()
         self.controller = catalog.Controller()
@@ -332,15 +334,15 @@ class TestCatalogApi(test_base.ControllerTest, test_base.MuranoApiTestCase):
             '/v1/catalog/packages/', params={'catalog': 'True'}))
         self.assertEqual(4, len(result['packages']))
 
-    def _test_package(self):
+    def _test_package(self, manifest='manifest.yaml'):
         package_dir = os.path.abspath(
             os.path.join(
                 __file__,
-                '../../../packages/test_packages/test.mpl.v1.app'
+                '../../../packages/test_packages/test.mpl.v1.app',
             )
         )
         pkg = load_utils.load_from_dir(
-            package_dir
+            package_dir, filename=manifest
         )
         package = {
             'fully_qualified_name': pkg.full_name,
@@ -360,6 +362,10 @@ class TestCatalogApi(test_base.ControllerTest, test_base.MuranoApiTestCase):
         }
         return pkg, package
 
+    def test_not_valid_logo(self):
+        self.assertRaises(exceptions.PackageLoadError,
+                          self._test_package, 'manifest_with_broken_logo.yaml')
+
     def test_load_package_with_supplier_info(self):
         self._set_policy_rules(
             {'get_package': '@'}

murano/tests/unit/packages/test_packages/test.mpl.v1.app/manifest_with_broken_logo.yaml

@@ -0,0 +1,19 @@
+Format: 1.0
+Type: Application
+FullName: test.mpl.v1.app
+Description: Test V1 Application
+Author: Test runner
+Tags: [Linux]
+Classes:
+  test.mpl.v1.app.Thing: Thing.yaml
+Logo: test_logo.png.not_valid
+UI: ui.yaml
+Supplier:
+  Name: Supplier Name
+  CompanyUrl:
+    Text: Example Company
+    Link: http://example.com
+  Logo: test_supplier_logo.png
+  Summary: Company summary goes here 
+  Description: Marked up company description goes here
+