Add support for Ubuntu 19.04 (#416)

README.md

@@ -105,6 +105,7 @@ The script supports these OS and architectures:
 |   Fedora 28  |   ❔  |  ✅  |   ❔   |   ❔  |
 | Ubuntu 16.04 |   ✅  |  ✅  |   ❌   |   ❌  |
 | Ubuntu 18.04 |   ❌  |  ✅  |   ✅   |   ✅  |
+| Ubuntu 19.04 |   ❌  |  ✅  |   ✅   |   ✅  |
 
 To be noted:
 

openvpn-install.sh

@@ -36,7 +36,7 @@ function checkOS () {
 			fi
 		elif [[ "$ID" == "ubuntu" ]];then
 			OS="ubuntu"
-			if [[ ! $VERSION_ID =~ (16.04|18.04) ]]; then
+			if [[ ! $VERSION_ID =~ (16.04|18.04|19.04) ]]; then
 				echo "⚠️ Your version of Ubuntu is not supported."
 				echo ""
 				echo "However, if you're using Ubuntu > 17 or beta, then you can continue."