Fixing typo

Author: michaeltryby

appveyor.yml

@@ -9,7 +9,7 @@ environment:
 
 install:
     - choco install swig
-    - appveyor-tools\secure-file -decrypt coveralls.yml.enc -secret %my_secret%
+    - appveyor-tools\secure-file -decrypt .coveralls.yml.enc -secret %my_secret%
     - "%PYTHON%\\python.exe -m pip install wheel tox"