node 5 compatibility

[kapolos]

Changing the ffi dependency to 2.0.0 allows rust-in-node to build on node 5 👍

# npm install

> ref@1.2.0 install /opt/test2/rust-in-node/node_modules/ref
> node-gyp rebuild

make: Entering directory `/opt/test2/rust-in-node/node_modules/ref/build'
  CXX(target) Release/obj.target/binding/src/binding.o
  SOLINK_MODULE(target) Release/obj.target/binding.node
  COPY Release/binding.node
make: Leaving directory `/opt/test2/rust-in-node/node_modules/ref/build'

> ffi@2.0.0 install /opt/test2/rust-in-node/node_modules/ffi
> node-gyp rebuild

make: Entering directory `/opt/test2/rust-in-node/node_modules/ffi/build'
  CC(target) Release/obj.target/ffi/deps/libffi/src/prep_cif.o
  CC(target) Release/obj.target/ffi/deps/libffi/src/types.o
  CC(target) Release/obj.target/ffi/deps/libffi/src/raw_api.o
  CC(target) Release/obj.target/ffi/deps/libffi/src/java_raw_api.o
  CC(target) Release/obj.target/ffi/deps/libffi/src/closures.o
../deps/libffi/src/closures.c: In function 'dlmmap_locked':
../deps/libffi/src/closures.c:421:17: warning: ignoring return value of 'ftruncate', declared with attribute warn_unused_result [-Wunused-result]
       ftruncate (execfd, offset);
                 ^
../deps/libffi/src/closures.c:433:17: warning: ignoring return value of 'ftruncate', declared with attribute warn_unused_result [-Wunused-result]
       ftruncate (execfd, offset);
                 ^
  CC(target) Release/obj.target/ffi/deps/libffi/src/x86/ffi.o
  CC(target) Release/obj.target/ffi/deps/libffi/src/x86/ffi64.o
../deps/libffi/src/x86/ffi64.c: In function 'classify_argument':
../deps/libffi/src/x86/ffi64.c:181:18: warning: suggest braces around empty body in an 'else' statement [-Wempty-body]
    FFI_ASSERT (0);
                  ^
  CC(target) Release/obj.target/ffi/deps/libffi/src/x86/unix64.o
  CC(target) Release/obj.target/ffi/deps/libffi/src/x86/sysv.o
  AR(target) Release/obj.target/deps/libffi/libffi.a
  COPY Release/libffi.a
  CXX(target) Release/obj.target/ffi_bindings/src/ffi.o
  CXX(target) Release/obj.target/ffi_bindings/src/callback_info.o
  CXX(target) Release/obj.target/ffi_bindings/src/threaded_callback_invokation.o
  SOLINK_MODULE(target) Release/obj.target/ffi_bindings.node
  COPY Release/ffi_bindings.node
make: Leaving directory `/opt/test2/rust-in-node/node_modules/ffi/build'

> ref@1.2.0 install /opt/test2/rust-in-node/node_modules/ref
> node-gyp rebuild

make: Entering directory `/opt/test2/rust-in-node/node_modules/ref/build'
  CXX(target) Release/obj.target/binding/src/binding.o
  SOLINK_MODULE(target) Release/obj.target/binding.node
  COPY Release/binding.node
make: Leaving directory `/opt/test2/rust-in-node/node_modules/ref/build'
embed@1.0.0 /opt/test2/rust-in-node
`-- ffi@2.0.0 
  +-- nan@2.1.0 
  +-- ref@1.2.0 
  | `-- nan@2.1.0 
  `-- ref-struct@1.0.2 

npm WARN EPACKAGEJSON embed@1.0.0 No repository field.

[wtfil]

Hi! Thx for comment! Let me update this module:)

[wtfil]

@kapolos just updated ffi and everything works fine for node@4.2.1 but there is an issue with node@5 (nodejs/node#3619)
Fix already in master so it will part of new minor update of node. Meanwhile, you can play with this repo and node@4.2.1
I am using this utility for quick navigation between versions https://www.npmjs.com/package/n

[kapolos]

@wtfil Awesome! 👍

Also, thanks for mentioning n, I have been using nvm but n looks great. 🍻