Improve README

Author: Robin Clart

README.md

@@ -13,19 +13,32 @@ back to us.
 This app provides a way for merit makers to donate money to a charity of their
 choosing using their credit card.
 
+At the root path you will find a list of charities, a field to enter an amount,
+and a series of credit card fields powered by omise. The amount must be sent in
+Thai Baht. But both Omise API and the total column in the charity table both expect an integer value in the smallest unit of the Thai Baht, the satang.
+
+Note that you must signup for an omise account and replace both pkey and skey
+in the `config/secrets.yml` file to use the app in development mode.
+
+To run the test simply run `rake test`. You'll notice that one test already
+fails. You'll have to fix the code (not the test) that produce this failure.
+
 ## Exercices
 
-  1. fix the race condition in the balance amount column;
-  2. refactor the code in the donate action of the website controller;
-  3. add a feature to allow a charity to be picked at random.
+  1. fix the race condition in the balance amount column
+  2. refactor and improve the code in the donate action
+  3. fix and add integration tests to allow subunits in the amount field
+  4. add a feature to allow a charity to be picked at random
+
+Bonus point: Remove all `Rails.env.test?` conditionals from the code.
 
 ## Principles
 
 We want you to focus on those three principles while writing code:
 clarity, simplicity and defensiveness.
 
 Clarity: write clear code that any devs could read and understand in one go.  
-Simplicity: write gimmic-free and straightforward code with no ambiguities.  
+Simplicity: write gimmick-free and straightforward code with no ambiguities.  
 Defensiveness: cover edge cases and treat user inputs with care.  
 
 ## Testing
@@ -36,6 +49,13 @@ the rest of the code you'll write in existing or newly created classes and
 modules. Note that we require that all tests must pass before we can invite you
 in for an interview.
 
+In test mode no network connection to Omise are made. In general we prefer
+duck-typing to make our test fast. In the codebase you'll notice that we use
+a bunch of conditionals that switch between doing call to the Omise library in
+normal use and constructing quick and dirty OpenStruct for test. Please keep it
+that way and make no network calls during the tests. But you're free to find
+another way to remove the conditionals as noted in the exercices list.
+
 ## Rules
 
 You can:
@@ -55,13 +75,13 @@ You can't:
 ## Submitting Your Code
 
 You must email your changes as a git patch to [email protected]. Your patch must
-consist of three separate commits. One commits per exercice. Your commit message
-must communicate clearly what has been done in each commit. Have a look at
-previous commits to have a clear idea of what we expect.
+consist of multiple separate commits. One commits per exercice. Your commit
+message must communicate clearly what has been done in each commit. Have a look
+at previous commits to have a clear idea of what we expect.
 
 If you notice more bugs in the original implementation you can add fixes for
-thoses as well. You won't be penalized if you don't. However we ask you not
-to add more features than the one given in the excercice list.
+those as well. You won't be penalized if you don't. However we ask you not
+to add more features than the one given in the exercise list.
 
 Note that we will outright reject any submission which does not follow the
 guidelines outlined in this README.