fix(models): make team member status nullable

See merge request !124

fix(server): fix bug where server crashes if teams are not defined

See merge request !94

feat(*): expose isEnvVariableTrue helper function

See merge request !93

fix(db-manager): fix immutability issue of db config so that it can be extended

See merge request !92

Pg ssl

See merge request !91

feat(db-manager): expose create tables command

See merge request !90

fix(*): make coko-server cli work

See merge request !89

feat(*): expose migrate as a function

See merge request !88

refactor(*): remove most pubsweet dependencies

See merge request !87

refactor(*): remove pubsweet-server dependency

See merge request !83

fix(server): andle oauth refresh token having 0 as its expiration value

See merge request !86

feat(*): add activity log service

See merge request !55