Fix issues in appveyor configuration

appveyor.yml

@@ -3,7 +3,7 @@ environment:
     # SDK v7.0 MSVC Express 2008's SetEnv.cmd script will fail if the
     # /E:ON and /V:ON options are not enabled in the batch script intepreter
     # See: http://stackoverflow.com/a/13751649/163740
-    CMD_IN_ENV: "cmd /E:ON /V:ON /C .\\appveyor\\run_with_env.cmd"
+    CMD_IN_ENV: "cmd /E:ON /V:ON /C run_with_env.cmd"
 
   matrix:
 
@@ -89,6 +89,10 @@ install:
   # the parent CMD process).
   - "SET PATH=%PYTHON%;%PYTHON%\\Scripts;%PATH%"
 
+  # Add appveyor folder to PATH for allowing run_with_env to be run from
+  # anywhere 
+  - "SET PATH=C:\\projects\\yara-python\\appveyor;%PATH%"
+
   # Check that we have the expected version and architecture for Python
   - "python --version"
   - "python -c \"import struct; print(struct.calcsize('P') * 8)\""