Add docs for AWS Lambda, SNS and SQS (#478)

* Add docs for AWS Lambda, SNS and SQS

* Improve SNS documentation

source/_components/notify.aws_lambda.markdown

@@ -0,0 +1,77 @@
+---
+layout: page
+title: "AWS Lambda"
+description: "Instructions how to invoke AWS Lambda functions from Home Assistant."
+date: 2016-05-14 16:35
+sidebar: true
+comments: false
+sharing: true
+footer: true
+logo: aws_lambda.png
+ha_category: Notifications
+ha_release: 0.20
+---
+
+The AWS Lambda notify platform enables invoking [AWS Lambda](https://aws.amazon.com/lambda/) functions.
+
+### Configuration
+
+```yaml
+# Example configuration.yaml entry
+notify:
+  platform: aws_lambda
+  name: NOTIFIER_NAME
+  aws_access_key_id: AWS_ACCESS_KEY_ID
+  aws_secret_access_key: AWS_SECRET_ACCESS_KEY
+  profile_name: AWS_PROFILE
+  region_name: 'us-east-1'
+  # Optional
+  context:
+    ...
+```
+
+Configuration variables:
+
+- **aws_access_key_id** (*Required if aws_secret_access_key is provided*): Your AWS Access Key ID. For more information, please read the [AWS General Reference regarding Security Credentials](http://docs.aws.amazon.com/general/latest/gr/aws-security-credentials.html). If provided, you must also provide an `aws_secret_access_key` and must **not** provide a `profile_name`.
+- **aws_secret_access_key** (*Required if aws_access_key_id is provided*): Your AWS Secret Access Key. For more information, please read the [AWS General Reference regarding Security Credentials](http://docs.aws.amazon.com/general/latest/gr/aws-security-credentials.html). If provided, you must also provide an `aws_access_key_id` and must **not** provide a `profile_name`.
+- **profile_name** (*Optional*): A credentials profile name. For more information, please see the [boto3 documentation section about credentials](http://boto3.readthedocs.io/en/latest/guide/configuration.html#shared-credentials-file).
+- **region_name** (*Required*): The region identifier to connect to. The default is `us-east-1`.
+- **name** (*Optional*): Setting the optional parameter `name` allows multiple notifiers to be created. The default value is `notify`. The notifier will bind to the service `notify.NOTIFIER_NAME`.
+- **context** (*Optional*): An optional dictionary you can provide to pass custom context through to the Lambda function. The `context` dictionary (if any) is combined with the same data available at the `/api/config` HTTP API route.
+
+### Usage
+
+AWS Lambda is a notify platform and thus can be controlled by calling the notify service [as described here](/components/notify/). It will invoke a Lambda for all targets given in the notification payload. A target can be formatted as a function name, an entire ARN ([Amazon Resource Name](http://docs.aws.amazon.com/general/latest/gr/aws-arns-and-namespaces.html)) or a partial ARN. For more information, please see the [boto3 docs](http://boto3.readthedocs.io/en/latest/reference/services/lambda.html#Lambda.Client.invoke).
+
+The Lambda event payload will contain everything passed in the service call payload. Here is an example payload that would be sent to Lambda:
+
+```json
+{
+  "title": "Test message!",
+  "target": "arn:aws:lambda:us-east-1:123456789012:function:ProcessKinesisRecords",
+  "data": {
+    "test": "okay"
+  },
+  "message": "Hello world!"
+}
+```
+
+The context will look like this:
+
+```json
+{
+  "hass": {
+    "components": ["recorder", "logger", "http", "logbook", "api", "frontend"],
+    "latitude": 44.1234,
+    "location_name": "Home",
+    "longitude": 5.5678,
+    "temperature_unit": "°C",
+    "time_zone": "Europe/Zurich",
+    "version": "0.20.0.dev0"
+  },
+  "custom": {
+    "two": "three",
+    "test": "one"
+  }
+}
+```