Fix crashes when path to prototype contains spaces

We had a user unable to use the migration script because the path to
their prototype included spaces. Fix this by not `spawn`ing via the
shell in `bin/cli`; we don't need to, and this way we don't need to
worry about escaping command line arguments.

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+### Fixes
+
+- [Fix crashes when path to prototype contains spaces](https://github.com/alphagov/govuk-prototype-kit/pull/1841)
+
 ## 13.0.1
 
 ### Fixes

bin/cli

@@ -153,7 +153,6 @@ function warnIfNpmStart (argv, env) {
 
     await spawn('npx', ['govuk-prototype-kit', 'init', '--', installDirectory], {
       cwd: installDirectory,
-      shell: true,
       stdio: 'inherit'
     })
   } else if (argv.command === 'init') {
@@ -212,7 +211,6 @@ function warnIfNpmStart (argv, env) {
       await prepareMigration(kitDependency, projectDirectory)
 
       await spawn('npx', ['govuk-prototype-kit', 'migrate', '--', projectDirectory], {
-        shell: true,
         stdio: 'inherit'
       })
     } else {

bin/utils/index.js

@@ -13,7 +13,6 @@ async function npmInstall (cwd, dependencies) {
       ...dependencies
     ], {
       cwd: cwd,
-      shell: true,
       stdio: 'inherit'
     })
 }