Fix utf-8 error on py 2.7

[Globegitter]

On our pre-production environment we just now got an error related to unicode encoding in the to_global_id code. I fixed it and added a test that ensures that behaviour works.

As a reference, this is the error one would see otherwise:

  File "/home/app/apps/killik_ops_dashboard.pex/third_party/python/graphql_relay/node/node.py", line 53, in to_global_id
    return base64(':'.join([type, str(id)]))
UnicodeEncodeError: 'ascii' codec can't encode character u'\u06ed' in position 39: ordinal not in range(128)

[coveralls]

Coverage increased (+0.007%) to 99.623% when pulling 71fe343 on Globegitter:to-global-id-unicode-error into c4c6533 on graphql-python:master.

[coveralls]

Coverage increased (+0.007%) to 99.623% when pulling 3b4de4f on Globegitter:to-global-id-unicode-error into c4c6533 on graphql-python:master.

[coveralls]

Coverage increased (+0.005%) to 99.62% when pulling 7a5ded4 on Globegitter:to-global-id-unicode-error into c4c6533 on graphql-python:master.

[coveralls]

Coverage increased (+0.006%) to 99.621% when pulling a67d78e on Globegitter:to-global-id-unicode-error into c4c6533 on graphql-python:master.

[coveralls]

Coverage increased (+0.006%) to 99.621% when pulling d852e75 on Globegitter:to-global-id-unicode-error into c4c6533 on graphql-python:master.

[coveralls]

Coverage increased (+0.007%) to 99.623% when pulling c348879 on Globegitter:to-global-id-unicode-error into c4c6533 on graphql-python:master.

[Globegitter]

This test failure was really strange - it happens to me locally also on master and seems to be a dict ordering consistency issue between py2 and py3. This sorted is not great but was the only way I managed to fix it.

[coveralls]

Coverage increased (+0.02%) to 99.636% when pulling 148575e on Globegitter:to-global-id-unicode-error into c4c6533 on graphql-python:master.

[Globegitter]

Noticed I did only fix it on the lower level, @syrusakbary is now ready to merge :)