Added version release notes.

Resolves issues with jQuery vulnerabilities in RDoc.

- [Ruby 2.6.4 Release Notes](https://is.gd/dNIrnn).
- [Multiple jQuery vulnerabilities in RDoc](https://is.gd/RNRZHr).

.ruby-version

@@ -1 +1 @@
-2.6.3
+2.6.4

CHANGES.md

@@ -1,3 +1,12 @@
+# 7.2.1 (2019-09-01)
+
+- Updated README screencast tutorial.
+- Updated to Ruby 2.6.4.
+
+# 7.2.0 (2019-08-01)
+
+- Added file install function.
+
 # 7.1.2 (2019-06-01)
 
 - Updated contributing documentation.

README.md

@@ -60,7 +60,7 @@ the two projects are meant to be used:
 
 ## Screencast
 
-[![asciicast](https://asciinema.org/a/155990.png)](https://asciinema.org/a/155990)
+[![asciicast](https://asciinema.org/a/263059.svg)](https://asciinema.org/a/263059)
 
 ## Requirements
 
@@ -76,7 +76,7 @@ Current Version (stable):
 
     git clone https://github.com/bkuhlmann/mac_os.git
     cd mac_os
-    git checkout 7.1.2
+    git checkout 7.2.1
 
 Master Version (unstable):
 

lib/installers.sh

@@ -123,7 +123,6 @@ install_program() {
   local install_path=$(get_install_path "$program_name")
 
   if [[ ! -e "$install_path" ]]; then
-    printf "Installing: $install_path...\n"
     download_file "$url" "$program_name"
     mv "$MAC_OS_WORK_PATH/$program_name" "$install_path"
     chmod 755 "$install_path"
@@ -172,6 +171,23 @@ install_git_project() {
 }
 export -f install_git_project
 
+# Installs a single file.
+# Parameters: $1 (required) - URL, $2 (required) - Install path.
+install_file() {
+  local file_url="$1"
+  local file_name=$(get_file_name "$1")
+  local install_path="$2"
+
+  if [[ ! -e "$install_path" ]]; then
+    download_file "$file_url" "$file_name"
+    mkdir -p $(dirname "$install_path")
+    mv "$MAC_OS_WORK_PATH/$file_name" "$install_path"
+    printf "Installed: $file_name.\n"
+    verify_path "$install_path"
+  fi
+}
+export -f install_file
+
 # Downloads remote file to local disk.
 # Parameters: $1 (required) - URL, $2 (required) - File name, $3 (optional) - HTTP header.
 download_file() {