Add model testing.

As a result of direction in the following comment:

> ansible#1458 (comment)

And the good work and lead of ansible#1436 in:

> ansible#1436

molecule/driver/linode.py

@@ -42,6 +42,10 @@ class Linode(base.Base):
           name: linode
         platforms:
           - name: instance
+            linode_id: 12345678
+            plan: 1
+            datacenter: 1
+            distribution: 129
 
     .. code-block:: bash
 

molecule/model/schema_v2.py

@@ -717,6 +717,36 @@ def pre_validate_base_schema(env, keep_string):
     },
 }
 
+platforms_linode_schema = {
+    'platforms': {
+        'type': 'list',
+        'schema': {
+            'type': 'dict',
+            'schema': {
+                'name': {
+                    'type': 'string',
+                },
+                'linode_id': {
+                    'type': 'integer',
+                    'required': True,
+                },
+                'plan': {
+                    'type': 'integer',
+                    'required': True,
+                },
+                'datacenter': {
+                    'type': 'integer',
+                    'required': True,
+                },
+                'distribution': {
+                    'type': 'integer',
+                    'required': True,
+                },
+            },
+        },
+    },
+}
+
 dependency_command_nullable_schema = {
     'dependency': {
         'type': 'dict',
@@ -870,6 +900,8 @@ def validate(c):
     elif c['driver']['name'] == 'vagrant':
         util.merge_dicts(schema, driver_vagrant_provider_section_schema)
         util.merge_dicts(schema, platforms_vagrant_schema)
+    elif c['driver']['name'] == 'linode':
+        util.merge_dicts(schema, platforms_linode_schema)
     else:
         util.merge_dicts(schema, platforms_base_schema)
 

test/unit/model/v2/test_platforms_section.py

@@ -327,3 +327,73 @@ def test_platforms_driver_name_required(_config):
     x = {'platforms': [{0: [{'name': ['required field']}]}]}
 
     assert x == schema_v2.validate(_config)
+
+
+@pytest.fixture
+def _model_platform_linode_section_data():
+    return {
+        'driver': {
+            'name': 'linode',
+        },
+        'platforms': [{
+            'name': str(),
+            'linode_id': int(),
+            'plan': int(),
+            'datacenter': int(),
+            'distribution': int(),
+        }]
+    }
+
+@pytest.mark.parametrize(
+    '_config', ['_model_platform_linode_section_data'], indirect=True)
+def test_platforms_linode(_config):
+    assert {} == schema_v2.validate(_config)
+
+
+@pytest.fixture
+def _model_platforms_linode_errors_section_data():
+    return {
+        'driver': {
+            'name': 'linode',
+        },
+        'platforms': [{
+            'name': int(),
+            'linode_id': str(),
+            'plan': str(),
+            'datacenter': str(),
+            'distribution': str(),
+        }]
+    }
+
+
+@pytest.mark.parametrize(
+    '_config', ['_model_platforms_linode_errors_section_data'], indirect=True)
+def test_platforms_linode_has_errors(_config):
+    x = {
+        'platforms': [{
+            0: [{
+                'name': ['must be of string type'],
+                'linode_id': ['must be of integer type'],
+                'plan': ['must be of integer type'],
+                'datacenter': ['must be of integer type'],
+                'distribution': ['must be of integer type'],
+            }],
+        }],
+    }
+
+    assert x == schema_v2.validate(_config)
+
+
+@pytest.mark.parametrize(
+    '_config', ['_model_platform_linode_section_data'], indirect=True)
+@pytest.mark.parametrize('_required_field', (
+    'linode_id',
+    'distribution',
+    'plan',
+    'datacenter',
+    'distribution',
+))
+def test_platforms_linode_fields_required(_config, _required_field):
+    del _config['platforms'][0][_required_field]
+    x = {'platforms': [{0: [{_required_field: ['required field']}]}]}
+    assert x == schema_v2.validate(_config)