remove useless dockerfile #395

Job	Run time
Build wheels	1m 22s
Build wheels	1m 22s
client-generation	3m 27s
client-generation	3m 27s
Unit test - ./extensions/gubbins/gubbins-core	1m 38s
Unit test - ./extensions/gubbins/gubbins-core	1m 38s
Unit test - ./extensions/gubbins/gubbins-db	1m 46s
Unit test - ./extensions/gubbins/gubbins-db	1m 46s
Unit test - ./extensions/gubbins/gubbins-routers	2m 9s
Unit test - ./extensions/gubbins/gubbins-routers	2m 9s
Unit test - ./extensions/gubbins/gubbins-client	1m 38s
Unit test - ./extensions/gubbins/gubbins-client	1m 38s
Unit test - ./extensions/gubbins/gubbins-cli	1m 44s
Unit test - ./extensions/gubbins/gubbins-cli	1m 44s
build-image	2m 42s
build-image	2m 42s
pytest-integration	12m 7s
pytest-integration	13m 55s
	58m 54s

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