add gcc-mingw-w64-i686 dep for travis

Author: nscaife

.travis.yml

@@ -2,7 +2,7 @@ language: c
 
 before_install:
     - sudo apt-get update -q
-    - sudo apt-get install gcc-mingw-w64-x86-64 binutils-mingw-w64 -y
+    - sudo apt-get install gcc-mingw-w64-x86-i686 gcc-mingw-w64-x86-64 binutils-mingw-w64 -y
 
 script:
     - cd libgnurx-2.5