Document how to install all dependencies on recent versions of Ubuntu

[emosenkis]

Other distros are also welcome

[luser]

Usually installing the build-essential metapackage is enough to build most simple software, that gives you gcc/g++ and make.

[iancoleman]

I'm installing on ubuntu 18.04 and the command pip for installing platformio failed. It needed to be changed to pip3 since python3 is default on this distro. Could be handy to check for presence of pip vs pip3.

edit: it requires python2.x, here's the error I got for pip3

Minimum supported version is 2.7, please upgrade Python.
Python 3 is not yet supported.

so ubuntu 18.04 requires installing python-pip, ie sudo apt-get install python-pip

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I also get an error when I rerun ./build.sh --install to resume installing platformio:

info: component 'rust-std' for target 'i686-unknown-linux-gnu' is up to date
Installing bindgen...
    Updating crates.io index
  Installing bindgen v0.48.1
error: binary `bindgen` already exists in destination as part of `bindgen v0.48.1`
Add --force to overwrite

I got around it by commenting out that line of the install script. It'd be nice to be able to run the script multiple times without it throwing errors.

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I also had to install libclang-7-dev as a dependency of bindgen, ie sudo apt-get install libclang-7-dev, without this it was not possible to initialize a new project because bindgen --version failed.