Updated esp8266 core causes declaration conflict in neopixel library.

[JamesNewton]

error: declaration of C function 'void rom_i2c_writeReg_Mask(uint32_t, uint32_t, uint32_t, uint32_t, uint32_t, uint32_t)' conflicts with void rom_i2c_writeReg_Mask(uint32_t block, uint32_t host_id, uint32_t reg_add, uint32_t Msb, uint32_t Lsb, uint32_t indata);

https://github.com/Makuna/NeoPixelBus/issues/252

But his update doesn't help since you locked all the libraries in locally.