change reference_data.py to use tf.gfile (#3921)

* change reference_data.py to use tf.gfile

* simplify json treatment

* Update reference files to account for a superficial change in batch_norm

official/utils/testing/reference_data/resnet/batch-size-32_bottleneck_version-2_width-8_channels-4/tf_version.json

-["1.8.0-dev20180325", "v1.7.0-rc1-750-g6c1737e6c8"]
\ No newline at end of file
+["1.8.0-dev20180408", "v1.7.0-1345-gb874783ccd"]
\ No newline at end of file

official/utils/testing/reference_data/resnet/batch-size-32_building_projection_version-1_width-8_channels-4/results.json

-[32, 8, 8, 4, 0.5349493026733398, 0.5126370191574097, 4070.01220703125, 32, 4, 4, 8, 0.0, 1.4142168760299683, 2306.740478515625]
\ No newline at end of file
+[32, 8, 8, 4, 0.5349493026733398, 0.5126370191574097, 4070.01220703125, 32, 4, 4, 8, 0.0, 2.7680201530456543, 2341.23486328125]
\ No newline at end of file

official/utils/testing/reference_data/resnet/batch-size-32_building_projection_version-1_width-8_channels-4/tf_version.json

-["1.8.0-dev20180325", "v1.7.0-rc1-750-g6c1737e6c8"]
\ No newline at end of file
+["1.8.0-dev20180408", "v1.7.0-1345-gb874783ccd"]
\ No newline at end of file

official/utils/testing/reference_data/resnet/batch-size-32_building_projection_version-2_width-8_channels-4/results.json

-[32, 8, 8, 4, 0.7820245027542114, 0.8173515796661377, 4095.256591796875, 32, 4, 4, 8, -0.3681173324584961, 0.197183296084404, 213.7501678466797]
\ No newline at end of file
+[32, 8, 8, 4, 0.7820245027542114, 0.8173515796661377, 4095.256591796875, 32, 4, 4, 8, 0.0679062008857727, 0.009305447340011597, -137.36178588867188]
\ No newline at end of file

official/utils/testing/reference_data/resnet/batch-size-32_building_projection_version-2_width-8_channels-4/tf_version.json

-["1.8.0-dev20180325", "v1.7.0-rc1-750-g6c1737e6c8"]
\ No newline at end of file
+["1.8.0-dev20180408", "v1.7.0-1345-gb874783ccd"]
\ No newline at end of file

official/utils/testing/reference_data/resnet/batch-size-32_building_version-1_width-8_channels-4/results.json

-[32, 8, 8, 4, 0.23128163814544678, 0.22117376327514648, 4100.51806640625, 32, 8, 8, 4, 0.9646798372268677, 0.16614516079425812, 5799.6708984375]
\ No newline at end of file
+[32, 8, 8, 4, 0.23128163814544678, 0.22117376327514648, 4100.51806640625, 32, 8, 8, 4, 1.1768392324447632, 0.2728465795516968, 5832.6416015625]
\ No newline at end of file

official/utils/testing/reference_data/resnet/batch-size-32_building_version-1_width-8_channels-4/tf_version.json

-["1.8.0-dev20180325", "v1.7.0-rc1-750-g6c1737e6c8"]
\ No newline at end of file
+["1.8.0-dev20180408", "v1.7.0-1345-gb874783ccd"]
\ No newline at end of file

official/utils/testing/reference_data/resnet/batch-size-32_building_version-2_width-8_channels-4/results.json

-[32, 8, 8, 4, 0.7616699934005737, 0.5485763549804688, 4106.8720703125, 32, 8, 8, 4, 0.42806127667427063, 0.7305102348327637, 5319.9892578125]
\ No newline at end of file
+[32, 8, 8, 4, 0.7616699934005737, 0.5485763549804688, 4106.8720703125, 32, 8, 8, 4, -0.056346118450164795, 0.5792689919471741, 2972.37255859375]
\ No newline at end of file