fix: migrate lodash.assign to native Object.assign

[armano2]

Migrates use of lodash assign to native Object.assign, additionally i changed some imports as we don't have to import entire lodash package when we are using only one function from it

[coveralls]

Coverage: 94.77%. Remained the same when pulling 4b2e25f on armano2:lodash/assign into d0e5d59 on conventional-changelog:master.