Added local directives back into install script

bin/install

@@ -13,7 +13,7 @@ install_ripgrep() {
   local version=$2
   local install_path=$3
   local bin_install_path="$install_path/bin"
-  download_url="$(get_download_url "$version")"
+  local download_url; download_url="$(get_download_url "$version")"
 
   mkdir -p "${bin_install_path}"
 
@@ -28,8 +28,8 @@ install_ripgrep() {
 }
 
 get_arch() {
-  arch=$(uname -m | tr '[:upper:]' '[:lower:]')
-  platform="$(get_platform)"
+  local arch; arch=$(uname -m | tr '[:upper:]' '[:lower:]')
+  local platform; platform="$(get_platform)"
   case ${arch} in
   arm64)
     if [ "$platform" = "apple-darwin" ]; then
@@ -44,7 +44,7 @@ get_arch() {
 }
 
 get_platform() {
-  plat=$(uname | tr '[:upper:]' '[:lower:]')
+  local plat; plat=$(uname | tr '[:upper:]' '[:lower:]')
   case ${plat} in
   darwin)
     plat='apple-darwin'
@@ -62,8 +62,8 @@ get_platform() {
 
 get_download_url() {
   local version="$1"
-  arch="$(get_arch)"
-  platform="$(get_platform)"
+  local arch; arch="$(get_arch)"
+  local platform; platform="$(get_platform)"
   echo "https://github.com/BurntSushi/ripgrep/releases/download/${version}/ripgrep-${version}-${arch}-${platform}.tar.gz"
 }