Remove unused, open files at top level of tests.

The data read from the file was unused. The files remained opened and
were never explicitly closed.

Fixes some instances of warnings during tests:

"ResourceWarning: unclosed file ..."

Tests/test_file_fli.py

@@ -6,7 +6,6 @@ from PIL import Image, FliImagePlugin
 # created as an export of a palette image from Gimp2.6
 # save as...-> hopper.fli, default options.
 test_file = "Tests/images/hopper.fli"
-data = open(test_file, "rb").read()
 
 
 class TestFileFli(PillowTestCase):

Tests/test_file_icns.py

@@ -6,7 +6,6 @@ import sys
 
 # sample icon file
 TEST_FILE = "Tests/images/pillow.icns"
-data = open(TEST_FILE, "rb").read()
 
 enable_jpeg2k = hasattr(Image.core, 'jp2klib_version')
 

Tests/test_file_ico.py

@@ -5,7 +5,6 @@ from PIL import Image, IcoImagePlugin
 
 # sample ppm stream
 TEST_ICO_FILE = "Tests/images/hopper.ico"
-TEST_DATA = open(TEST_ICO_FILE, "rb").read()
 
 
 class TestFileIco(PillowTestCase):

Tests/test_file_png.py

@@ -12,7 +12,6 @@ codecs = dir(Image.core)
 # sample png stream
 
 TEST_PNG_FILE = "Tests/images/hopper.png"
-TEST_DATA = open(TEST_PNG_FILE, "rb").read()
 
 # stuff to create inline PNG images
 

Tests/test_file_ppm.py

@@ -4,7 +4,6 @@ from PIL import Image
 
 # sample ppm stream
 test_file = "Tests/images/hopper.ppm"
-data = open(test_file, "rb").read()
 
 
 class TestFilePpm(PillowTestCase):

Tests/test_file_psd.py

@@ -4,7 +4,6 @@ from PIL import Image, PsdImagePlugin
 
 # sample ppm stream
 test_file = "Tests/images/hopper.psd"
-data = open(test_file, "rb").read()
 
 
 class TestImagePsd(PillowTestCase):