Add pwd path to jar's one

The flow is:
1. clone repo e.g. to ```~/android/tools/dex-count```
2. give shell the alias like ```alias DEX_COUNT="~/android/tools/dex-count/dex-method-counts"
->
Run from your android-project root DEX_COUNT app/build/outputs/apk/myapp.apk
Merge pull request #4 from almozavr/patch-1

Allow script to be run from another directory.