Fix project environment modifications (#36)

* Upgrade pio version

Signed-off-by: acuadros95 <acuadros1995@gmail.com>

* Revert changes

* Remove space

Author: Acuadros95

README.md

@@ -45,6 +45,7 @@ The community is encouraged to open pull request with custom use cases.
 ## Requirements
 
 - PlatformIO [local installation](https://docs.platformio.org/en/stable/core/installation.html) or [PlatformIO IDE for VSCode](https://platformio.org/install/ide?install=vscode)
+- PlatformIO Core version 6.1.0 or greater
 - PlatformIO needs  `git`, `cmake` and `pip3` to handle micro-ROS internal dependencies:
 
   ```bash

extra_script.py

@@ -1,3 +1,4 @@
+Import("projenv")
 Import("env")
 
 import os
@@ -129,8 +130,8 @@ def build_microros(*args, **kwargs):
         main_path + "/platform_code/{}/{}".format(framework, microros_transport)])
 
     # Add micro-ROS defines to user application
-    global_env.Append(CPPDEFINES=[('MICRO_ROS_TRANSPORT_{}_{}'.format(framework.upper(), microros_transport.upper()), 1)])
-    global_env.Append(CPPDEFINES=[('MICRO_ROS_DISTRO_ {} '.format(microros_distro.upper()), 1)])
+    projenv.Append(CPPDEFINES=[('MICRO_ROS_TRANSPORT_{}_{}'.format(framework.upper(), microros_transport.upper()), 1)])
+    projenv.Append(CPPDEFINES=[('MICRO_ROS_DISTRO_{} '.format(microros_distro.upper()), 1)])
 
     # Include path for framework
     global_env.Append(CPPPATH=[main_path + "/platform_code/{}".format(framework)])