jgitver-configuration-v1_1_0.xsd restricts SCRIPT strategy usage

## Issue

**version**: 1.7.0

**usage context**:

- [x ] maven command line: 3.6.3

**Problem description**:
Hello! I wanted to add functionality allowing version extraction from a release branch name.
I thought that the SCRIPT strategy will be applicable and useful for this task.
It does work with version 1.7.0, but the xml schema validation highlights the value SCRIPT as incorrect as well as it doesn't recognize and tags themselves when using jgitver-configuration-v1_1_0.xsd.
That confused me a bit. That is not that big of a trouble, but probably jgitver-configuration-v1_1_0.xsd requires update
As I see now it allows only three strategies to be configured in jgitver.config.xml
"...
<xs:restriction>
<xs:enumeration value="MAVEN"/>
<xs:enumeration value="CONFIGURABLE"/>
<xs:enumeration value="PATTERN"/>
</xs:restriction> "

Thank you for the product!

Best regards,
vladismat