Add fixes for compiling on Windows
Update .travis.yml
Update .travis.yml

Put back 'only master' command on branch
Add in ignore file
Remove field.c as this is generated by cython on demand
Allow windows compilation to work with Mingw

Compilation should now work with MSVC and mingw (32-bit)
Merge pull request #4 from stestagg/windowsfix

Fix compilation on Windows using MSVC, and MinGW 32-bit