Fix typos

Author: chorrell

README.md

@@ -1,6 +1,6 @@
 # docker-image-testing-example
 
-This is an exmaple of using Serverspec to test Dockerfiles
+This is an example of using Serverspec to test Dockerfiles
 
 ## Setup
 
@@ -10,7 +10,7 @@ Install Serverspec and the require gems with bundler:
 bundle install
 ```
 
-This exmaple assumes you have Docker installed, running and configured.
+This example assumes you have Docker installed, running and configured.
 
 ## Usage (running the tests)
 
@@ -20,22 +20,22 @@ bundle exec rake
 
 The above will run Serverspec and using the docker-api gem it will
 
-- Build a Docker image from the Docker file found in the top level dictrories (4.4 and 6.3)
+- Build a Docker image from the Docker file found in the top level directories (4.4 and 6.3)
 - Create a container of that image,
 - Run the tests found in `spec/` on the container
 - Delete the images and containers if the test was successful
 
-The Dockerfiles are based on the offiial [docker-node](https://github.com/nodejs/docker-node) image.
+The Dockerfiles are based on the official [docker-node](https://github.com/nodejs/docker-node) image.
 
-You could also use the docker-api gem to pull exisiting images from the Docker hub and run tests against that image.
+You could also use the docker-api gem to pull existing images from the Docker hub and run tests against that image.
 
 So for instance, a pull_image helper could look something like this:
 
 ```ruby
   def pull_image(image)
 
     puts "Pulling image #{image}..."
-    @image = Docker::Image.create('fromImage' => imge)
+    @image = Docker::Image.create('fromImage' => image)
 
     set :os, :family => 'debian'
     set :backend, :docker