adjust specs to work locally and on github actions ci

spec/installer2_spec.sh

@@ -11,7 +11,7 @@ Describe 'installer2.sh'
   }
 
   mock_unwritable_directory() {
-    DIRECTORY="/usr/local/bin" # requires root/sudo
+    DIRECTORY="/usr/local/testing-installer" # requires root/sudo
   }
 
   BeforeEach 'setup'
@@ -70,10 +70,10 @@ Commands:
     Describe 'when unwritable directory'
       Before 'mock_unwritable_directory'
 
-      It 'is false (1) to /usr/local/bin (typical case that /usr/local/bin is not writable)'
+      It 'is false (1) to /usr/local/testing-installer (typical case that /usr/local/testing-installer is not writable)'
         When call is_directory_writable
         The status should equal 1
-        The output should equal "[INSTALLATION_FAILED] the installation directory [/usr/local/bin] is not writable by the current user
+        The output should equal "[INSTALLATION_FAILED] the installation directory [/usr/local/testing-installer] is not writable by the current user
 ? run as root [sudo $0] or choose a writable directory like your current directory [$0 directory=.]"
       End
     End