Prefer /usr/bin/env and searching from PATH

test/quotes.t

@@ -130,7 +130,7 @@ class TestBug1436(TestCase):
 
            This problem is entirely testing artifact, and not Taskwarrior.
         """
-        self.echo = Task(taskw=utils.binary_location("/bin/echo"))
+        self.echo = Task(taskw=utils.binary_location("echo", USE_PATH=True))
 
         # One level of backshashes gets eaten by bash
         # Verify with: $ echo xxx \\\\yyy zzz

test/tw-1883.t

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # Test for TW-1883 (#1896 on Github)
 # https://github.com/GothenburgBitFactory/taskwarrior/issues/1896
 

test/tw-1895.t

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 . bash_tap_tw.sh
 

test/tw-2124.t

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # A test case for TW-2124.
 # https://github.com/GothenburgBitFactory/taskwarrior/issues/2124
 

test/tw-2257.t

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 . bash_tap_tw.sh
 

test/tw-2386.t

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 . bash_tap_tw.sh