Hack around problems using leiningen 2.3.4 with lein-droid

After upgrading lein-droid to 2.3.4-SNAPSHOT (built from master) I started getting an error about not being able to locate `leiningen.release`. This commit works around it by just copying the needed code from leiningen.

This is probably not the right way to fix it. Maybe lein-droid depends on a later version of leiningen or something.

Thanks!

```
java.io.FileNotFoundException: Could not locate leiningen/release__init.class or leiningen/release.clj on classpath:                                                                                                                                                                                                                                              [282/1881]
        at clojure.lang.RT.load(RT.java:443)
        at clojure.lang.RT.load(RT.java:411)
        at clojure.core$load$fn__5018.invoke(core.clj:5530)
        at clojure.core$load.doInvoke(core.clj:5529)
        at clojure.lang.RestFn.invoke(RestFn.java:408)
        at clojure.core$load_one.invoke(core.clj:5336)
        at clojure.core$load_lib$fn__4967.invoke(core.clj:5375)
        at clojure.core$load_lib.doInvoke(core.clj:5374)
        at clojure.lang.RestFn.applyTo(RestFn.java:142)
        at clojure.core$apply.invoke(core.clj:619)
        at clojure.core$load_libs.doInvoke(core.clj:5413)
        at clojure.lang.RestFn.applyTo(RestFn.java:137)
        at clojure.core$apply.invoke(core.clj:621)
        at clojure.core$use.doInvoke(core.clj:5507)
        at clojure.lang.RestFn.invoke(RestFn.java:457)
        at leiningen.droid.manifest$eval2561$loading__4910__auto____2562.invoke(manifest.clj:1)
        at leiningen.droid.manifest$eval2561.invoke(manifest.clj:1)
        at clojure.lang.Compiler.eval(Compiler.java:6619)
        at clojure.lang.Compiler.eval(Compiler.java:6608)
        at clojure.lang.Compiler.load(Compiler.java:7064)
        at clojure.lang.RT.loadResourceScript(RT.java:370)
        at clojure.lang.RT.loadResourceScript(RT.java:361)
        at clojure.lang.RT.load(RT.java:440)
        at clojure.lang.RT.load(RT.java:411)
        at clojure.core$load$fn__5018.invoke(core.clj:5530)
        at clojure.core$load.doInvoke(core.clj:5529)
        at clojure.lang.RestFn.invoke(RestFn.java:408)
        at clojure.core$load_one.invoke(core.clj:5336)
        at clojure.core$load_lib$fn__4967.invoke(core.clj:5375)
        at clojure.core$load_lib.doInvoke(core.clj:5374)
        at clojure.lang.RestFn.applyTo(RestFn.java:142)
        at clojure.core$apply.invoke(core.clj:619)
        at clojure.core$load_libs.doInvoke(core.clj:5413)
        at clojure.lang.RestFn.applyTo(RestFn.java:137)
        at clojure.core$apply.invoke(core.clj:621)
        at clojure.core$use.doInvoke(core.clj:5507)
        at clojure.lang.RestFn.invoke(RestFn.java:457)
        at leiningen.droid.compile$eval2400$loading__4910__auto____2401.invoke(compile.clj:1)
        at leiningen.droid.compile$eval2400.invoke(compile.clj:1)
        at clojure.lang.Compiler.eval(Compiler.java:6619)
        at clojure.lang.Compiler.eval(Compiler.java:6608)
        at clojure.lang.Compiler.load(Compiler.java:7064)
        at clojure.lang.RT.loadResourceScript(RT.java:370)
        at clojure.lang.RT.loadResourceScript(RT.java:361)
        at clojure.lang.RT.load(RT.java:440)
        at clojure.lang.RT.load(RT.java:411)
        at clojure.core$load$fn__5018.invoke(core.clj:5530)
        at clojure.core$load.doInvoke(core.clj:5529)
        at clojure.lang.RestFn.invoke(RestFn.java:408)
        at clojure.core$load_one.invoke(core.clj:5336)
        at clojure.core$load_lib$fn__4967.invoke(core.clj:5375)
        at clojure.core$load_lib.doInvoke(core.clj:5374)
        at clojure.lang.RestFn.applyTo(RestFn.java:142)
        at clojure.core$apply.invoke(core.clj:619)
        at clojure.core$load_libs.doInvoke(core.clj:5413)
        at clojure.lang.RestFn.applyTo(RestFn.java:137)
        at clojure.core$apply.invoke(core.clj:621)
        at clojure.core$use.doInvoke(core.clj:5507)
        at clojure.lang.RestFn.invoke(RestFn.java:512)
        at leiningen.droid$eval2351$loading__4910__auto____2352.invoke(droid.clj:5)
        at leiningen.droid$eval2351.invoke(droid.clj:5)
        at clojure.lang.Compiler.eval(Compiler.java:6619)
        at clojure.lang.Compiler.eval(Compiler.java:6608)
        at clojure.lang.Compiler.load(Compiler.java:7064)
        at clojure.lang.RT.loadResourceScript(RT.java:370)
        at clojure.lang.RT.loadResourceScript(RT.java:361)
        at clojure.lang.RT.load(RT.java:440)
        at clojure.lang.RT.load(RT.java:411)
        at clojure.core$load$fn__5018.invoke(core.clj:5530)
        at clojure.core$load.doInvoke(core.clj:5529)
        at clojure.lang.RestFn.invoke(RestFn.java:408)
        at clojure.core$load_one.invoke(core.clj:5336)
        at clojure.core$load_lib$fn__4967.invoke(core.clj:5375)
        at clojure.core$load_lib.doInvoke(core.clj:5374)
        at clojure.lang.RestFn.applyTo(RestFn.java:142)
        at clojure.core$apply.invoke(core.clj:619)
        at clojure.core$load_libs.doInvoke(core.clj:5413)
        at clojure.lang.RestFn.applyTo(RestFn.java:137)
        at clojure.core$apply.invoke(core.clj:619)
        at clojure.core$require.doInvoke(core.clj:5496)
        at clojure.lang.RestFn.invoke(RestFn.java:408)
        at leiningen.core.utils$require_resolve.invoke(utils.clj:60)
        at leiningen.core.utils$require_resolve.invoke(utils.clj:62)
        at leiningen.core.main$resolve_task.invoke(main.clj:187)
        at leiningen.core.main$resolve_task.invoke(main.clj:192)
        at leiningen.core.main$apply_task.invoke(main.clj:221)
        at leiningen.core.main$resolve_and_apply.invoke(main.clj:234)
        at leiningen.core.main$_main$fn__3092.invoke(main.clj:303)
        at leiningen.core.main$_main.doInvoke(main.clj:290)
        at clojure.lang.RestFn.invoke(RestFn.java:421)
        at clojure.lang.Var.invoke(Var.java:419)
        at clojure.lang.AFn.applyToHelper(AFn.java:163)
        at clojure.lang.Var.applyTo(Var.java:532)
        at clojure.core$apply.invoke(core.clj:617)
        at clojure.main$main_opt.invoke(main.clj:335)
        at clojure.main$main.doInvoke(main.clj:440)
        at clojure.lang.RestFn.invoke(RestFn.java:457)
        at clojure.lang.Var.invoke(Var.java:427)
        at clojure.lang.AFn.applyToHelper(AFn.java:172)
        at clojure.lang.Var.applyTo(Var.java:532)
        at clojure.main.main(main.java:37)
```