jni library naming issue on linux

Hi, I build J2V8 from master on CentOS 7 and Debian 9 because official 4.8.0 jni library cannot work on CentOS 7 (cpp library issue) .

.so file name like
```
root@debian-vm:~# unzip -l J2V8/build.out/j2v8_linux_x86_64-4.8.0-SNAPSHOT.jar |grep lib
20876360 2018-03-19 08:58 libj2v8-linux-x86_64.so
```

But in LibraryLoader
```
private static String computeLibraryShortName() {
String base = "j2v8";
String osSuffix = getOS();
String archSuffix = getArchSuffix();
return base + "_" + osSuffix + "_" + archSuffix;
}

```

Then the J2V8 library looks for libj2v8_linux_x86_64.so, tests failed like
```

[ERROR] testArrayTypedArrayValue_Int16Array(com.eclipsesource.v8.utils.V8ObjectUtilsTest) Time elapsed: 0 s <<< ERROR!
java.lang.IllegalStateException: J2V8 native library not loaded
at com.eclipsesource.v8.utils.V8ObjectUtilsTest.seutp(V8ObjectUtilsTest.java:54)
Caused by: java.lang.UnsatisfiedLinkError:
Could not load J2V8 library. Reasons:
no libj2v8_linux_x86_64.so in java.library.path
no j2v8_linux_x86_64 in java.library.path

at com.eclipsesource.v8.utils.V8ObjectUtilsTest.seutp(V8ObjectUtilsTest.java:54)

```

But I saw in official release, it's named using '_'.
```
root@debian-vm:/tmp# unzip -l j2v8_linux_x86_64-4.8.0.jar |grep lib
21334920 2017-06-19 18:17 libj2v8_linux_x86_64.so
```

Am I missing something?