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

tests/rules/test_terraform_init.py

@@ -0,0 +1,33 @@
+import pytest
+from thefuck.rules.terraform_init import match, get_new_command
+from thefuck.types import Command
+
+
+@pytest.mark.parametrize('script, output', [
+    ('terraform plan', 'Error: Initialization required. '
+                       'Please see the error message above.'),
+    ('terraform plan', 'This module is not yet installed. Run "terraform init" '
+                       'to install all modules required by this configuration.'),
+    ('terraform apply', 'Error: Initialization required. '
+                        'Please see the error message above.'),
+    ('terraform apply', 'This module is not yet installed. Run "terraform init" '
+                        'to install all modules required by this configuration.')])
+def test_match(script, output):
+    assert match(Command(script, output))
+
+
+@pytest.mark.parametrize('script, output', [
+    ('terraform --version', 'Terraform v0.12.2'),
+    ('terraform plan', 'No changes. Infrastructure is up-to-date.'),
+    ('terraform apply', 'Apply complete! Resources: 0 added, 0 changed, 0 destroyed.'),
+])
+def test_not_match(script, output):
+    assert not match(Command(script, output=output))
+
+
+@pytest.mark.parametrize('command, new_command', [
+    (Command('terraform plan', ''), 'terraform init && terraform plan'),
+    (Command('terraform apply', ''), 'terraform init && terraform apply'),
+])
+def test_get_new_command(command, new_command):
+    assert get_new_command(command) == new_command