Use standard directories when running on Linux (#91)

* Use standard Linux directories for application data (https://en.wikipedia.org/wiki/Filesystem_Hierarchy_Standard)

* Use standard system directories

* Cleanup all Polaris files during uninstall

* Expose get_pid_directory to rest of the crate

* Add separate targets for install binary and data files, clean up makefile

* Use environment variables for directory locations during install process

* On Linux, read locations from environment variables at compile time

* Split static_directory in two (web and swagger directories)

* Follow recommendations from the Make manual

* Avoid redundant directories

* Added workflow to validate installer setup

* Added CLI options to locate log file, pid file and cache directory

* Fixed an issue where build command did not support the xdg/system switch

* Renamed log option to log-level

* Fixed an issue where xdg install would do a system build

* Use re-usable action to make linux release

* Avoid nested actions (see https://github.com/actions/runner/issues/646)

* Updated installation instructions

* Replaced deprecated use of set-env

res/unix/release_script.sh

@@ -6,8 +6,7 @@ echo "Copying package files"
 cp -r web docs/swagger src migrations test-data Cargo.toml Cargo.lock res/unix/Makefile release/tmp/polaris
 
 echo "Creating tarball"
-POLARIS_VERSION=$(grep -m 1 ^version Cargo.toml | awk '{print $3}' | tr -d '"\r\n')
-tar -zc -C release/tmp -f release/Polaris_$POLARIS_VERSION.tar.gz polaris
+tar -zc -C release/tmp -f release/polaris.tar.gz polaris
 
 echo "Cleaning up"
 rm -rf release/tmp