add 'create table' support

- added support for create table operation
```
jedlik
.tablename('tablename')
.hashkey('hashkey', null, 'S')
.rangekey('rangekey', null, null, 'N')
.throughput({read: 5, write: 7})
.createTable())
```

- added ability to specify hash and range keys types directly without inferring them from the value
- (misc.) removed end-of-line whitespaces