#!/bin/bash shebang in executable (#483)

Add #!/bin/bash to `clean` script across star, binary and astero, for consistency with rn, re, etc.

Author: gautam-404

astero/clean

@@ -1,2 +1,4 @@
+#!/bin/bash
+
 cd make; make clean
-cd ../test/make; make clean
+cd ../test/make; make clean

astero/mk

@@ -1 +1,3 @@
-cd make; make
+#!/bin/bash
+
+cd make; make

astero/test_suite/astero_adipls/clean

@@ -1,2 +1,4 @@
+#! /bin/bash
+
 cd make
 make clean

astero/test_suite/astero_gyre/clean

@@ -1,2 +1,4 @@
+#! /bin/bash
+
 cd make
 make clean

astero/test_suite/example_astero/clean

@@ -1,2 +1,4 @@
+#! /bin/bash
+
 cd make
 make clean

astero/test_suite/fast_from_file/clean

@@ -1,2 +1,4 @@
+#! /bin/bash
+
 cd make
 make clean

astero/test_suite/fast_newuoa/clean

@@ -1,2 +1,4 @@
+#! /bin/bash
+
 cd make
 make clean

astero/test_suite/fast_scan_grid/clean

@@ -1,2 +1,4 @@
+#! /bin/bash
+
 cd make
 make clean

astero/test_suite/fast_simplex/clean

@@ -1,2 +1,4 @@
+#! /bin/bash
+
 cd make
 make clean

astero/test_suite/surface_effects/clean

@@ -1,2 +1,4 @@
+#! /bin/bash
+
 cd make
 make clean