Fix project_root_dir

[olegs]

At the moment util.sh script contains the following code:

PROJECT_ROOT_DIR="$(expand_path "$(dirname $0)/..")"
project_root_dir() {
    echo ${PROJECT_ROOT_DIR}
}

Which is incorrect for many cases (see downstream folder) after #40 is introduced

[olegs]

Main problem is that $0 depends not on file location, but on first callee file location. Consider the following example at folder /Users/oleg/test: files foo.sh and bar/bar.sh. foo.sh

source bar/bar.sh
PROJECT_ROOT=$(project_root)
echo "$PROJECT_ROOT"

bar/bar.sh

function expand_path() {
    # expand ".." and "." including trailing case
    # based on https://stackoverflow.com/questions/3915040/bash-fish-command-to-print-absolute-path-to-a-file
    TARGET_FILE="$(pwd)/$1"

    if [ -d "$1" ]; then
        # dir
        TARGET_FILE="$(cd "$1"; pwd)"
    elif [ -f "$1" ]; then
        # file
        if [[ $1 == */* ]]; then
            TARGET_FILE="$(cd "${1%/*}"; pwd)/${1##*/}"
        fi
    fi
    # Compute the canonicalized name by finding the physical path
    # for the directory we're in and appending the target file.
    PHYS_DIR="$(pwd -P)"
    echo "${PHYS_DIR}/${TARGET_FILE}"
}

_PROJECT_ROOT_BAR="$(expand_path "$(dirname $0)")"
echo "_PROJECT_ROOT_BAR: ${_PROJECT_ROOT_BAR}"
project_root() {
    echo ${_PROJECT_ROOT_BAR}
}

2 calls results in different project_root results.

unit-809:test oleg$ bash foo.sh
_PROJECT_ROOT_BAR: /Users/oleg/test
/Users/oleg/test
unit-809:test oleg$ bash bar/bar.sh
_PROJECT_ROOT_BAR: /Users/oleg/test/bar