Add Spined Megalodon

Fixes #82

lib/magic/cards/spined_megalodon.rb

@@ -0,0 +1,31 @@
+module Magic
+  module Cards
+    class SpinedMegalodon < Creature
+      card_name "Spined Megalodon"
+      creature_type "Shark"
+      cost generic: 5, blue: 2
+      power 5
+      toughness 7
+
+      keywords :hexproof
+
+      class ScryTrigger < TriggeredAbility::Base
+        def should_perform?
+          return false if event.attacks.none? { |attack| attack.attacker == actor }
+          true
+        end
+
+        def call
+          actor.add_choice(:scry, actor: actor)
+        end
+      end
+
+
+      def event_handlers
+        {
+          Events::PreliminaryAttackersDeclared => ScryTrigger
+        }
+      end
+    end
+  end
+end

spec/cards/spined_megalodon_spec.rb

@@ -0,0 +1,26 @@
+require "spec_helper"
+
+RSpec.describe Magic::Cards::SpinedMegalodon do
+  include_context "two player game"
+
+  let(:permanent) { ResolvePermanent("Spined Megalodon") }
+
+  it "has hexproof" do
+    expect(permanent).to be_hexproof
+  end
+
+  it "scries 1 when it attacks" do
+    skip_to_combat!
+
+    current_turn.declare_attackers!
+
+    p1.declare_attacker(
+      attacker: permanent,
+      target: p2
+    )
+
+    current_turn.attackers_declared!
+
+    expect(game.choices.first).to be_a(Magic::Choice::Scry)
+  end
+end