Created CloudEvent class

CloudEvents is a more pythonic interface for using cloud events.
It is powered by internal marshallers and cloud event base classes.
It performs basic validation on fields, and cloud event type checking.

Signed-off-by: Curtis Mason <cumason@google.com>

Author: Curtis Mason

.github/ISSUE_TEMPLATE.md

@@ -0,0 +1,16 @@
+## Expected Behavior
+
+
+## Actual Behavior
+
+
+## Steps to Reproduce the Problem
+
+1.
+2.
+3.
+
+## Specifications
+
+- Platform:
+- Python Version:

.github/pull_request_template.md

@@ -1,9 +1,10 @@
-- Link to issue this resolves
+Fixes #<issuelink>
 
-- What I did
+## Changes
 
-- How I did it
 
-- How to verify it
+## One line description for the changelog
 
-- One line description for the changelog
+
+- [ ] Tests pass
+- [ ] Appropriate changes to README are included in PR

README.md

@@ -6,10 +6,9 @@ This SDK is still considered a work in progress, therefore things might (and
 will) break with every update.
 
 This SDK current supports the following versions of CloudEvents:
+
 - v1.0
 - v0.3
-- v0.2
-- v0.1
 
 ## Python SDK
 
@@ -116,7 +115,6 @@ In this topic you'd find various example how to integrate an SDK with various HT
 
 One of popular framework is [`requests`](http://docs.python-requests.org/en/master/).
 
-
 #### CloudEvent to request
 
 The code below shows how integrate both libraries in order to convert a CloudEvent into an HTTP request:
@@ -155,27 +153,29 @@ Complete example of turning a CloudEvent into a request you can find [here](samp
 #### Request to CloudEvent
 
 The code below shows how integrate both libraries in order to create a CloudEvent from an HTTP request:
+
 ```python
     response = requests.get(url)
     response.raise_for_status()
     headers = response.headers
     data = io.BytesIO(response.content)
-    event = v02.Event()
+    event = v1.Event()
     http_marshaller = marshaller.NewDefaultHTTPMarshaller()
     event = http_marshaller.FromRequest(
         event, headers, data, json.load)
 
 ```
-Complete example of turning a CloudEvent into a request you can find [here](samples/python-requests/request_to_cloudevent.py).
 
+Complete example of turning a CloudEvent into a request you can find [here](samples/python-requests/request_to_cloudevent.py).
 
 ## SDK versioning
 
 The goal of this package is to provide support for all released versions of CloudEvents, ideally while maintaining
 the same API. It will use semantic versioning with following rules:
-* MAJOR version increments when backwards incompatible changes is introduced.
-* MINOR version increments when backwards compatible feature is introduced INCLUDING support for new CloudEvents version.
-* PATCH version increments when a backwards compatible bug fix is introduced.
+
+- MAJOR version increments when backwards incompatible changes is introduced.
+- MINOR version increments when backwards compatible feature is introduced INCLUDING support for new CloudEvents version.
+- PATCH version increments when a backwards compatible bug fix is introduced.
 
 ## Community
 

cloudevents/sdk/converters/binary.py

@@ -17,13 +17,13 @@
 from cloudevents.sdk import exceptions
 from cloudevents.sdk.converters import base
 from cloudevents.sdk.event import base as event_base
-from cloudevents.sdk.event import v02, v03, v1
+from cloudevents.sdk.event import v03, v1
 
 
 class BinaryHTTPCloudEventConverter(base.Converter):
 
     TYPE = "binary"
-    SUPPORTED_VERSIONS = [v02.Event, v03.Event, v1.Event]
+    SUPPORTED_VERSIONS = [v03.Event, v1.Event]
 
     def can_read(self, content_type: str) -> bool:
         return True

cloudevents/sdk/event/base.py

@@ -16,6 +16,21 @@
 import json
 import typing
 
+_ce_required_fields = {
+    'id',
+    'source',
+    'type',
+    'specversion'
+}
+
+
+_ce_optional_fields = {
+    'datacontenttype',
+    'schema',
+    'subject',
+    'time'
+}
+
 
 # TODO(slinkydeveloper) is this really needed?
 class EventGetterSetter(object):
@@ -117,6 +132,7 @@ def MarshalJSON(self, data_marshaller: typing.Callable) -> typing.IO:
 
     def UnmarshalJSON(self, b: typing.IO, data_unmarshaller: typing.Callable):
         raw_ce = json.load(b)
+
         for name, value in raw_ce.items():
             if name == "data":
                 value = data_unmarshaller(value)
@@ -134,7 +150,6 @@ def UnmarshalBinary(
                 self.SetContentType(value)
             elif header.startswith("ce-"):
                 self.Set(header[3:], value)
-
         self.Set("data", data_unmarshaller(body))
 
     def MarshalBinary(