Fix cancellation typos

CHANGELOG.md

@@ -48,7 +48,7 @@ Version 2.0.0-beta3 *(2016-01-05)*
    `client(OkHttpClient)` method on `Retrofit.Builder` still exists as a convenience.
  * New: `isExecuted()` method returns whether a `Call` has been synchronously or asynchronously executed.
  * New: `isCanceled()` method returns whether a `Call` has been canceled. Use this in `onFailure` to determine
-   whether the callback was invoked from cancelation or actual transport failure.
+   whether the callback was invoked from cancellation or actual transport failure.
  * New: `converter-scalars` module provides a `Converter.Factory` for converting `String`, the 8 primitive
    types, and the 8 boxed primitive types as `text/plain` bodies. Install this before your normal converter
    to avoid passing these simple scalars through, for example, a JSON converter.

retrofit/src/main/java/retrofit2/ExecutorCallAdapterFactory.java

@@ -60,7 +60,7 @@ static final class ExecutorCallbackCall<T> implements Call<T> {
           callbackExecutor.execute(new Runnable() {
             @Override public void run() {
               if (delegate.isCanceled()) {
-                // Emulate OkHttp's behavior of throwing/delivering an IOException on cancelation
+                // Emulate OkHttp's behavior of throwing/delivering an IOException on cancellation.
                 callback.onFailure(call, new IOException("Canceled"));
               } else {
                 callback.onResponse(call, response);