ITT: Exception asserts readme info added.

Author: dmitry-ivanov

README.md

@@ -185,6 +185,16 @@ $this->dontSeeInDatabaseMany('posts', [
 ]);
 ```
 
+### ExceptionAsserts
+
+#### `willSeeException()`
+
+Adding expectation that exception of the specified class, with specified message and specified code will be thrown:
+
+```php
+$this->willSeeException(RuntimeException::class, 'Oops! Houston, we have a problem!');
+```
+
 ### LogFileAsserts
 
 #### `assertLogFileExists()`