Update PATH environment variable to add .dotnet and php composer default folder (#477)

* Add environment variables for .dotnet and php comopser

* update rust.sh comments

images/linux/scripts/installers/rust.sh

@@ -14,8 +14,7 @@ export CARGO_HOME=/usr/share/rust/.cargo
 
 curl https://sh.rustup.rs -sSf | sh -s -- -y
 
-# Add Cargo and Rust binaries to the machine path
+# Initialize environment variables
-echo "PATH=${CARGO_HOME}/bin:$PATH" | tee -a /etc/environment
 source $CARGO_HOME/env
 
 # Install common tools

images/linux/scripts/installers/updatepath.sh

@@ -0,0 +1,6 @@
+#!/bin/bash
+
+CARGO_HOME=/usr/share/rust/.cargo
+DOTNET_TOOLS_HOME=/home/runner/.dotnet/tools
+PHP_COMPOSER_HOME=/home/runner/.config/composer/vendor/bin
+echo "PATH=${CARGO_HOME}/bin:${PATH}:${DOTNET_TOOLS_HOME}:${PHP_COMPOSER_HOME}" | tee -a /etc/environment

images/linux/ubuntu1604.json

@@ -167,6 +167,7 @@
                 "{{template_dir}}/scripts/installers/terraform.sh",
                 "{{template_dir}}/scripts/installers/vcpkg.sh",
                 "{{template_dir}}/scripts/installers/zeit-now.sh",
+                "{{template_dir}}/scripts/installers/updatepath.sh",
                 "{{template_dir}}/scripts/installers/dpkg-config.sh"
 
             ],

images/linux/ubuntu1804.json

@@ -170,6 +170,7 @@
                 "{{template_dir}}/scripts/installers/terraform.sh",
                 "{{template_dir}}/scripts/installers/vcpkg.sh",
                 "{{template_dir}}/scripts/installers/zeit-now.sh",
+                "{{template_dir}}/scripts/installers/updatepath.sh",
                 "{{template_dir}}/scripts/installers/dpkg-config.sh"
             ],
             "environment_vars": [