Use offical ubuntu image for Docker
Update mruby
fix mistaken usage of ngx_pstrdup().

ngx_pstrdup does not allocate a region
for null terminated character(+1).
fix error handlings when initialization.
Merge pull request #99 from cubicdaiya/issues/reduce_alloc2

fix mistaken usage of ngx_pstrdup().
Merge pull request #100 from cubicdaiya/issues/error_handlings

fix error handlings when initialization.
Update mruby
Implement new test system
Update mruby
Use mruby-simplehttp for ngx_mruby test
Update mruby
Update mruby
Update nginx version for travis ci and test
Update mruby
Update mruby
Update mruby
UPdate mruby
Update nginx version to v1.7.6
Update mruby
fix partial match of header name