The two parties did come together in order to form a unity government for the purpose of holding elections. Natanyahu and other Israeli politicians stated that they would never allow this reconciliation between Hamas and Fatah to occur, and that Hamas must be excluded from Palestinian elections, as they are regarded as a terrorist group by Israel. Shortly after that, there was another cycle of violence and escalation, a couple of Palestinian teenagers were killed at an anti occupation protest, then three Israeli teens were hitchhiking in the occupied West Bank, kidnapped and killed, followed by a Palestinian teen being kidnapped and burned alive. Israel then invaded the West Bank, and began arresting (or kidnapping depending on your perspective) hundreds of Palestinians it suspected of links to Hamas (political, militant or civil service employees, some countries distinguish between the militant wing and political/civil wing, like the UK, China, Russia, others do not like America and Canada). The stated aims of these raids were to locate and rescue the kidnapped teens, however later reports revealed that Israelis were aware that the teenagers had been already been killed. This led to the usual cycle of violence we're sadly all to familiar with. Hamas indiscriminate rocket attacks against Israel cities, and Israeli ground invasion and bombing campaigns in Gaza.
And the elections? They never happened. The Unity government, which actually consisted of neither Hamas nor Fatah members collapsed a year later due to Fatah unilaterally withdrawing, stating that it had no authority in Gaza. I suspect this was in no small part due to pressure from America, Israel, Saudi Arabia, UAE and other regional players who all wish to marginalize Hamas due to their ties to the Muslim brotherhood and Fatah's dependence on them for funding.
http://america.aljazeera.com/articles/2015/6/19/palestinian-political-crisis-deepens-with-collapse-of-unity-government.html