Bug fixes and unit tests for models/issue_label (#802)

models/fixtures/comment.yml

@@ -0,0 +1,7 @@
+-
+  id: 1
+  type: 7 # label
+  poster_id: 2
+  issue_id: 1
+  label_id: 1
+  content: "1"

models/fixtures/issue.yml

@@ -44,3 +44,13 @@
   content: content4
   is_closed: true
   is_pull: false
+
+-
+  id: 5
+  repo_id: 1
+  index: 4
+  poster_id: 2
+  name: issue5
+  content: content5
+  is_closed: true
+  is_pull: false

models/fixtures/issue_label.yml

@@ -0,0 +1,14 @@
+-
+  id: 1
+  issue_id: 1
+  label_id: 1
+
+-
+  id: 2
+  issue_id: 5
+  label_id: 2
+
+-
+  id: 3
+  issue_id: 2
+  label_id: 1

models/fixtures/label.yml

@@ -0,0 +1,15 @@
+-
+  id: 1
+  repo_id: 1
+  name: label1
+  color: '#abcdef'
+  num_issues: 2
+  num_closed_issues: 0
+
+-
+  id: 2
+  repo_id: 1
+  name: label2
+  color: '#000000'
+  num_issues: 1
+  num_closed_issues: 1