fix FileNotFoundException / add ignore file list (#68)

* fix FileNotFoundException

magisk patch boot, ramdisk add backup file don't create(add) parent dir

* add git ignore file

add ignore file list :
boot.img*
local.properties

.gitignore

@@ -1,3 +1,5 @@
 .idea
 .gradle
 build/
+boot.img*
+local.properties

bbootimg/src/main/kotlin/bootimg/cpio/AndroidCpio.kt

@@ -239,7 +239,7 @@ class AndroidCpio {
                     }
                     entry.isRegularFile -> {
                         entryInfo.note = ("REG " + entryInfo.note)
-                        File(outEntryName).writeBytes(buffer)
+                        File(outEntryName).also { it.parentFile.mkdirs() }.writeBytes(buffer)
                         if (EnvironmentVerifier().isWindows) {
                             //Windows: Posix not supported
                         } else {