use nan@2.14.0 to fix building

[harduino]

There was error in building in node 12.16.1 because of old version of nan

In file included from ../src/time.cc:5:
In file included from ../../nan/nan.h:223:
In file included from ../../nan/nan_new.h:189:
../../nan/nan_implementation_12_inl.h:356:37: error: too few arguments to function call, expected 2, have 1
return v8::StringObject::New(value).Asv8::StringObject();
~~~~~~~~~~~~~~~~~~~~~ ^
/Users/macos/Library/Caches/node-gyp/12.16.1/include/node/v8.h:5531:3: note: 'New' declared here
static Local New(Isolate* isolate, Local value);
^
In file included from ../src/time.cc:5:
In file included from ../../nan/nan.h:223:
In file included from ../../nan/nan_new.h:189:
../../nan/nan_implementation_12_inl.h:356:58: error: expected '(' for function-style cast or type construction
return v8::StringObject::New(value).Asv8::StringObject();
~~~~~~~~~~~~~~~~^
../../nan/nan_implementation_12_inl.h:356:60: error: expected expression
return v8::StringObject::New(value).Asv8::StringObject();
^
In file included from ../src/time.cc:5:
In file included from ../../nan/nan.h:2722:
../../nan/nan_object_wrap.h:24:25: error: no member named 'IsNearDeath' in 'Nan::Persistent<v8::Object, v8::NonCopyablePersistentTraitsv8::Object >'
assert(persistent().IsNearDeath());
~~~~~~~~~~~~ ^
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/assert.h:93:25: note: expanded from macro 'assert'
(__builtin_expect(!(e), 0) ? _assert_rtn(func, FILE, LINE, #e) : (void)0)
^
In file included from ../src/time.cc:5:
In file included from ../../nan/nan.h:2722:
../../nan/nan_object_wrap.h:127:26: error: no member named 'IsNearDeath' in 'Nan::Persistent<v8::Object, v8::NonCopyablePersistentTraitsv8::Object >'
assert(wrap->handle.IsNearDeath());
~~~~~~~~~~~~~ ^
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/assert.h:93:25: note: expanded from macro 'assert'
(__builtin_expect(!(e), 0) ? __assert_rtn(func, FILE, LINE, #e) : (void)0)