Bump semver from 6.3.0 to 6.3.1

Bumps [semver](https://github.com/npm/node-semver) from 6.3.0 to 6.3.1.
- [Release notes](https://github.com/npm/node-semver/releases)
- [Changelog](https://github.com/npm/node-semver/blob/v6.3.1/CHANGELOG.md)
- [Commits](https://github.com/npm/node-semver/compare/v6.3.0...v6.3.1)

---
updated-dependencies:
- dependency-name: semver
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>

__test__/verify-sparse-checkout-non-cone-mode.sh

@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 
 # Verify .git folder
 if [ ! -d "./sparse-checkout-non-cone-mode/.git" ]; then

__test__/verify-sparse-checkout.sh

@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 
 # Verify .git folder
 if [ ! -d "./sparse-checkout/.git" ]; then