Reindenting. (#17)

I normally prefer tabs for everything, it's nice to have the ability to
set to whatever your preferred width is. Since this project uses a lot
of yaml stuff I've had to indent those tests with spaces, for
consistency's sake I've decided to use spaces everywhere.

.prettierrc

@@ -1,6 +1,7 @@
 printWidth: 80
+tabWidth: 4
 singleQuote: true
-useTabs: true
+useTabs: false
 trailingComma: none
 bracketSpacing: true
 jsxBracketSameLine: true