Add a history endpoint

This is a very basic history endpoint as described in the issue #39

This doesn't support all the filters that are described in the
documentation provided here
https://documenter.getpostman.com/view/2025350/RWaEzAiG#9f1dfdc0-fbe8-4ae5-9209-7f3d649a627c
but it does support the basic functionality of retrieving all the
historical events or a specific historical event by passing an id

lib/spacex.rb

@@ -4,13 +4,14 @@
 require 'hashie'
 
 require_relative 'spacex/base_request'
-require_relative 'spacex/version'
-require_relative 'spacex/launches'
+require_relative 'spacex/capsules'
 require_relative 'spacex/company_info'
-require_relative 'spacex/roadster'
+require_relative 'spacex/cores'
 require_relative 'spacex/dragon_capsules'
-require_relative 'spacex/ships'
+require_relative 'spacex/history'
+require_relative 'spacex/launches'
 require_relative 'spacex/missions'
+require_relative 'spacex/roadster'
 require_relative 'spacex/rockets'
-require_relative 'spacex/capsules'
-require_relative 'spacex/cores'
+require_relative 'spacex/ships'
+require_relative 'spacex/version'

lib/spacex/history.rb

@@ -0,0 +1,7 @@
+module SPACEX
+  module History
+    def self.info(id = nil)
+      SPACEX::BaseRequest.info("history/#{id}")
+    end
+  end
+end

spec/spacex/history_spec.rb

@@ -0,0 +1,50 @@
+require 'spec_helper'
+
+describe SPACEX::History do
+  context '#info', vcr: { cassette_name: 'history/info' } do
+    subject do
+      SPACEX::History.info
+    end
+
+    it 'returns all historical events when no id is passed' do
+      first_subject = subject.first
+      expect(first_subject.id).to eq 1
+      expect(first_subject.title).to eq 'Falcon 1 Makes History'
+      expect(first_subject.event_date_utc).to eq '2008-09-28T23:15:00Z'
+      expect(first_subject.event_date_unix).to eq 1_222_643_700
+      expect(first_subject.flight_number).to eq 4
+      expect(first_subject.details).to eq(
+        'Falcon 1 becomes the first privately '\
+        'developed liquid fuel rocket to reach Earth orbit.'
+      )
+      expect(first_subject.links).to eq(
+        'reddit' => nil,
+        'article' => 'http://www.spacex.com/news/2013/02/11/flight-4-launch-update-0',
+        'wikipedia' => 'https://en.wikipedia.org/wiki/Falcon_1'
+      )
+    end
+  end
+
+  context "#info('4')", vcr: { cassette_name: 'history/info/4' } do
+    subject do
+      SPACEX::History.info(4)
+    end
+
+    it 'returns Historical event info for event id 4' do
+      expect(subject.id).to eq 4
+      expect(subject.title).to eq 'Falcon 9 First Flight'
+      expect(subject.event_date_utc).to eq '2010-06-04T18:45:00Z'
+      expect(subject.event_date_unix).to eq 1_275_677_100
+      expect(subject.flight_number).to eq 6
+      expect(subject.details).to eq(
+        'Met 100% of mission objectives on the first flight!'
+      )
+      expect(subject.links).to eq(
+        'reddit' => nil,
+        'article' => 'http://www.bbc.com/news/10209704',
+        'wikipedia' =>
+          'https://en.wikipedia.org/wiki/Dragon_Spacecraft_Qualification_Unit'
+      )
+    end
+  end
+end