Adding GAIN_PAIR and LOSE_PAIR actions to ReactionRecipe
Adding GAIN_PAIR and LOSE_PAIR actions to ReactionRecipe

These action will be first used in the lone_electron_pair_bond reaction
family

- GAIN_PAIR increases the number of lone electron pairs on a specific
atom
- LOSE_PAIR decreases the number of lone electron pairs on a specific
atom
comocheng/RMG-Py,chatelak/RMG-Py,comocheng/RMG-Py,faribas/RMG-Py,faribas/RMG-Py,nickvandewiele/RMG-Py,pierrelb/RMG-Py,enochd/RMG-Py,nickvandewiele/RMG-Py,nyee/RMG-Py,pierrelb/RMG-Py,enochd/RMG-Py,KEHANG/RMG-Py,chatelak/RMG-Py,KEHANG/RMG-Py,nyee/RMG-Py