修复：unit不包含dataset正确返回以及字段验证

app/forms/projects/datasets/create_form.rb

@@ -0,0 +1,15 @@
+class Projects::Datasets::CreateForm < BaseForm
+  attr_accessor :title, :description, :license_id, :paper_content
+  
+
+  validates :title, presence: true, length: { maximum: 100 }
+  validates :description, presence: true, length: { maximum: 500 }
+  validates :paper_content, length: { maximum: 500 }
+
+  validate :check_license
+
+  def check_license
+    raise "license_id值无效. " if license_id && License.find_by(id: license_id).blank?
+  end
+
+end