Remove tasks to upgrade to version 1.3.0

These tasks are not needed for new installations, and in existing
installations they've already been executed when upgrading to version
1.3.0.

spec/lib/tasks/db_spec.rb

@@ -1,70 +0,0 @@
-require "rails_helper"
-
-describe "rake db:load_sdg" do
-  before { Rake::Task["db:load_sdg"].reenable }
-
-  let :run_rake_task do
-    Rake.application.invoke_task("db:load_sdg")
-  end
-
-  it "populates empty databases and assigns targets correctly" do
-    SDG::Goal.destroy_all
-    SDG::Phase.destroy_all
-
-    run_rake_task
-
-    expect(SDG::Goal.count).to eq 17
-    expect(SDG::Target.count).to eq 169
-    expect(SDG::Target["17.1"].goal.code).to eq 17
-    expect(SDG::Phase.count).to eq 3
-  end
-
-  it "does not create additional records on populated databases" do
-    expect(SDG::Goal.count).to eq 17
-    expect(SDG::Target.count).to eq 169
-    expect(SDG::Phase.count).to eq 3
-
-    goal_id = SDG::Goal.last.id
-    target_id = SDG::Target.last.id
-    phase_id = SDG::Phase.last.id
-
-    run_rake_task
-
-    expect(SDG::Goal.count).to eq 17
-    expect(SDG::Target.count).to eq 169
-    expect(SDG::Phase.count).to eq 3
-    expect(SDG::Goal.last.id).to eq goal_id
-    expect(SDG::Target.last.id).to eq target_id
-    expect(SDG::Phase.last.id).to eq phase_id
-  end
-end
-
-describe "rake db:calculate_tsv" do
-  before { Rake::Task["db:calculate_tsv"].reenable }
-
-  let :run_rake_task do
-    Rake.application.invoke_task("db:calculate_tsv")
-  end
-
-  it "calculates the tsvector for polls" do
-    poll = create(:poll)
-    poll.update_column(:tsv, nil)
-
-    expect(poll.reload.tsv).to be nil
-
-    run_rake_task
-
-    expect(poll.reload.tsv).not_to be nil
-  end
-
-  it "calculates the tsvector for legislation processes" do
-    process = create(:legislation_process)
-    process.update_column(:tsv, nil)
-
-    expect(process.reload.tsv).to be nil
-
-    run_rake_task
-
-    expect(process.reload.tsv).not_to be nil
-  end
-end