Fix warning: Using the raise_error matcher without providing a specific error

spec/hooks_spec.rb

@@ -15,7 +15,7 @@ describe Pry::Hooks do
     it 'should not allow adding of a hook with a duplicate name' do
       @hooks.add_hook(:test_hook, :my_name) {}
 
-      expect { @hooks.add_hook(:test_hook, :my_name) {} }.to raise_error
+      expect { @hooks.add_hook(:test_hook, :my_name) {} }.to raise_error ArgumentError
     end
 
     it 'should create a new hook with a block' do

spec/pry_spec.rb

@@ -102,7 +102,7 @@ describe Pry do
 
       # bug fix for https://github.com/pry/pry/issues/93
       it 'should not leak pry constants into Object namespace' do
-        expect { pry_eval(Object.new, "Command") }.to raise_error
+        expect { pry_eval(Object.new, "Command") }.to raise_error NameError
       end
 
       it 'should be able to operate inside the BasicObject class' do