Merge pull request #3 from jhermann/patch-1

typo

Author: hpk42

pluggy.py

@@ -40,7 +40,7 @@
   is possible to register plugins for which a hook specification is not yet
   known and validate all hooks when the system is in a more referentially
   consistent state.  Setting an "optionalhook" attribution to a hook
-  implementation will avoid PluginValidationError's if a specifcation
+  implementation will avoid PluginValidationError's if a specification
   is missing.  This allows to have optional integration between plugins.
 
 - a "hook" relay object from which you can launch 1:N calls to