[CHORE] Add an interactive console for the gem and add pry as a development dependency (#13)

* Add an interactive console for the gem and add pry as a development dependency

* Add note to README

Author: maschwenk

Diff for: Gemfile.lock

@@ -7,10 +7,15 @@ GEM
   remote: https://rubygems.org/
   specs:
     ast (2.3.0)
+    coderay (1.1.1)
     diff-lcs (1.3)
+    method_source (0.9.0)
     parser (2.4.0.0)
       ast (~> 2.2)
     powerpack (0.1.1)
+    pry (0.11.3)
+      coderay (~> 1.1.0)
+      method_source (~> 0.9.0)
     rainbow (2.2.1)
     rake (11.3.0)
     rspec (3.5.0)
@@ -40,10 +45,11 @@ PLATFORMS
 
 DEPENDENCIES
   bundler (~> 1.14)
+  pry
   rake
   rspec
   rubocop (~> 0.48)
   vrt!
 
 BUNDLED WITH
-   1.15.3
+   1.16.0

Diff for: README.md

@@ -21,6 +21,14 @@ rails generate vrt:install
 ```
 
 ## Usage
+
+For convenience in development, we provide a utility for spinning up a
+playground for playing with the gem. You can invoke it with:
+
+```bash
+bin/console
+```
+
 When one has a VRT Classification ID, one can check it's validity:
 ```ruby
 vrt = VRT::Map.new

Diff for: bin/console

@@ -0,0 +1,9 @@
+#!/usr/bin/env ruby
+
+require 'bundler/setup'
+require 'vrt'
+require 'pry'
+
+# An interactive console for the VRT gem
+
+Pry.start

Diff for: vrt.gemspec

@@ -22,4 +22,5 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'rake'
   spec.add_development_dependency 'rspec'
   spec.add_development_dependency 'rubocop', '~> 0.48'
+  spec.add_development_dependency 'pry'
 end