Add install check for libpython3-dev and build-essential (martomi#171)

install.sh

@@ -1,3 +1,8 @@
+# Function that checks if a package is installed locally
+function package_installed() {
+  return dpkg -l "$1" &> /dev/null
+}
+
 # Check Python version
 if ! python3 -c 'import sys; assert sys.version_info >= (3,7)' 2> /dev/null;
 then
@@ -6,6 +11,12 @@ then
   exit 1
 fi
 
+# Check existence of required python build packages
+if ! package_installed libpython3-dev || ! package_installed build-essential; then
+  sudo apt-get update
+  sudo apt-get install libpython3-dev build-essential -y
+fi
+
 # Create virtual environment
 python3 -m venv venv