[Travis] Test against MRI 1.9.3.
[Travis] Test against MRI 1.9.3.

jafrog/bunny,gferguson-gd/bunny,pressrelations/bunny,pressrelations/bunny,0xfaded/bunny,wconrad/bunny,bartj3/bunny,bartj3/bunny,teodor-pripoae/bunny,wconrad/bunny,0xfaded/bunny,gferguson-gd/bunny,teodor-pripoae/bunny,jafrog/bunny