Split dev_seeds into individual files for sections

Why:

Its a really huge script, and conflicts are hard to resolve on forks,
with indivudal scripts its easier to make custom changes.

How:

Following @mariacheca example using require_relative and a file under
the db/dev_seeds/ folder

db/dev_seeds/communities.rb

@@ -0,0 +1,22 @@
+section "Creating Communities" do
+  Proposal.all.each { |proposal| proposal.update(community: Community.create) }
+  Budget::Investment.all.each { |investment| investment.update(community: Community.create) }
+end
+
+section "Creating Communities Topics" do
+  Community.all.each do |community|
+    Topic.create(community: community, author: User.all.sample,
+                 title: Faker::Lorem.sentence(3).truncate(60), description: Faker::Lorem.sentence)
+  end
+end
+
+section "Commenting Community Topics" do
+  30.times do
+    author = User.all.sample
+    topic = Topic.all.sample
+    Comment.create!(user: author,
+                    created_at: rand(topic.created_at..Time.current),
+                    commentable: topic,
+                    body: Faker::Lorem.sentence)
+  end
+end