THRIFT-2849: spelling errors fixed using codespell tool

Client: All
Patch: Anatol Pomozov

This closes #281
diff --git a/test/DocTest.thrift b/test/DocTest.thrift
index c93ac3b..9d19855 100644
--- a/test/DocTest.thrift
+++ b/test/DocTest.thrift
@@ -155,7 +155,7 @@
 typedef i32 TrivialMultiLine
 
 /**
- * This is the cannonical example
+ * This is the canonical example
  * of a multiline docstring.
  */
 typedef i32 StandardMultiLine