Changed Hashbang (#979)

Closes #893

Author: gautamprikshit1

tests/fixtures/bare_repo.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 set -eu -o pipefail
 
 git init -q --bare

tests/fixtures/basic_repo.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 set -eu -o pipefail
 
 git init -q

tests/fixtures/repo.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 set -eu -o pipefail
 
 git init -q