Undefined names: Add missing imports

[cclauss]

flake8 testing of https://github.com/IBM/rl-testbed-for-energyplus on Python 3.7.0

$ flake8 . --count --select=E901,E999,F821,F822,F823 --show-source --statistics

./baselines_energyplus/common/plot_energyplus.py:24:9: F821 undefined name 'os'
        os.exit(1)
        ^
./baselines_energyplus/bench/monitor.py:140:55: F821 undefined name 'uuid'
    mon_file = "/tmp/baselines-test-%s.monitor.csv" % uuid.uuid4()
                                                      ^
./baselines_energyplus/bench/monitor.py:156:20: F821 undefined name 'pandas'
    last_logline = pandas.read_csv(f, index_col=None)
                   ^
./baselines_energyplus/bench/monitor.py:159:5: F821 undefined name 'os'
    os.remove(mon_file)    ^
./gym_energyplus/envs/energyplus_model_2ZoneDataCenterHVAC_wEconomizer_Temp.py:553:222: F821 undefined name 'In22_25_1'
                f.write('"{}" {:5.2f} {:5.2f} {:5.2f} {:4.2f} {:5.2f} {:5.2f} {:5.2f} {:4.2f} {:5.2f} {:9.2f} {:8.3%} {:8.3%} {:3d}\n'.format(self.weather_key, Ave1, Min1, Max1, STD1, Ave2,  Min2, Max2, STD2, Rew, Power, In22_25_1, In22_25_2, ep))
                                                                                                                                                                                                                             ^
./gym_energyplus/envs/energyplus_model.py:228:17: F823 local variable 'time' (defined in enclosing scope on line 6) referenced before assignment
                time.sleep(1)
                ^
5     F821 undefined name 'uuid'
1     F823 local variable 'time' (defined in enclosing scope on line 6) referenced before assignment
6

[takaomoriyama]

Thanks for the reports. Now all patches have been taken.