Added rules to run terraform init before terraform plan or apply (#924)

* Run terraform init to initialize terraform modules

* Fix indent

* Add unit tests for terraform_init.py

thefuck/rules/terraform_init.py

@@ -0,0 +1,13 @@
+from thefuck.shells import shell
+from thefuck.utils import for_app
+
+
+@for_app('terraform')
+def match(command):
+    return ('this module is not yet installed' in command.output.lower() or
+            'initialization required' in command.output.lower()
+            )
+
+
+def get_new_command(command):
+    return shell.and_('terraform init', command.script)