Update to platformio v.2.1.1

[Jason2866]

For some platforms esptool flash fails. platformio/platform-espressif8266#149
Fixed in v.2.1.1

Description:

Related issue (if applicable): fixes #

Checklist:

• The pull request is done against the latest dev branch
• Only relevant files were touched (Also remember to update changelog.ino file)
• Only one feature/fix was added per PR.
• The code change is tested and works.
• The code change pass travis tests. Your PR cannot be merged unless tests pass
• I accept the CLA.