Implement Comparison Operators

[mboudreau]

In current version 0.1.2, only these following operators have been implemented: LT,LE,GT,GE and BETWEEN

The rest needs to be added.

[rrutt]

The .scan method also supports IN.
The .query method also supports IN, BEGINS_WITH, and CONTAINS via the method ItemRangeGroup.filterItemsByRangeKeyCondition as of Pull Request 50

#50

[rrutt]

As part of Pull Request 66 I added support for the BETWEEN, BEGINS_WITH, and CONTAINS to the scan filter, and corrected the GE scan filter's comparison direction.

#66

Note that comparisons for numeric attributes are still treated as string values, so that 2 GT 10 because "2" > "10" when using a string comparison. Similarly 123 CONTAINS 2 because "123".contains("2")