Fixed calculating relative values.

Fixed calculating relative values.

Added method to clear session cache to tracker.

Merge pull request #171 from pirsch-analytics/referrer-cities

Merge Referrer and locate Cities

Merge pull request #158 from pirsch-analytics/v2.7

v3.0

Fixed session cache.

Updated dependencies.

Changed hashing algorithm to SHA256.

Merge pull request #149 from pirsch-analytics/v2.6

v2.6

Fixed usage of TrackerConfig.SessionMaxAge.