Improve project build time setting validation

app/models/project.rb

@@ -368,8 +368,10 @@ class Project < ActiveRecord::Base
   chronic_duration_attr :build_timeout_human_readable, :build_timeout, default: 3600
   validates :build_timeout, allow_nil: true,
-                            numericality: { greater_than_or_equal_to: 600,
-                                            message: 'needs to be at least 10 minutes' }
+                            numericality: { greater_than_or_equal_to: 10.minutes,
+                                            less_than: 1.month,
+                                            only_integer: true,
+                                            message: 'needs to be beetween 10 minutes and 1 month' }
   # Returns a collection of projects that is either public or visible to the
   # logged in user.

spec/models/project_spec.rb

@@ -149,23 +149,25 @@ describe Project do
     it { is_expected.to validate_presence_of(:name) }
     it { is_expected.to validate_uniqueness_of(:name).scoped_to(:namespace_id) }
     it { is_expected.to validate_length_of(:name).is_at_most(255) }
-
     it { is_expected.to validate_presence_of(:path) }
     it { is_expected.to validate_length_of(:path).is_at_most(255) }
-
     it { is_expected.to validate_length_of(:description).is_at_most(2000) }
-
     it { is_expected.to validate_length_of(:ci_config_path).is_at_most(255) }
     it { is_expected.to allow_value('').for(:ci_config_path) }
     it { is_expected.not_to allow_value('test/../foo').for(:ci_config_path) }
     it { is_expected.not_to allow_value('/test/foo').for(:ci_config_path) }
-
     it { is_expected.to validate_presence_of(:creator) }
-
     it { is_expected.to validate_presence_of(:namespace) }
-
     it { is_expected.to validate_presence_of(:repository_storage) }
+    it 'validates build timeout constraints' do
+      is_expected.to validate_numericality_of(:build_timeout)
+        .only_integer
+        .is_greater_than_or_equal_to(10.minutes)
+        .is_less_than(1.month)
+        .with_message('needs to be beetween 10 minutes and 1 month')
+    end
+
     it 'does not allow new projects beyond user limits' do
       project2 = build(:project)
       allow(project2).to receive(:creator).and_return(double(can_create_project?: false, projects_limit: 0).as_null_object)