NXTP v0.1.5

What's Changed

• Merge main to adding-unit-tests by @liu-zhipeng in #662
• [sdk] reset history for contract writer mock fn by @jakekidd in #666
• [txservice] Check that transaction exists when mine timeout occurs. by @jakekidd in #655
• [sdk] Resort to using router network if gelato fails; set default useRelayers = false by @jakekidd in #664
• [sdk][router][txservice] fee cleanup by @sanchaymittal in #652
• merge main to adding-unit-tests by @liu-zhipeng in #667
• Adding unit tests by @liu-zhipeng in #668

Full Changelog: v0.1.4...v0.1.5