Please fix the following 'cros lint' errors:

toolchain-utils/crosperf/machine_image_manager_unittest.py
************* Module machine_image_manager_unittest
C: 49, 0: Unnecessary parens after 'print' keyword (superfluous-parens)
R:  1, 0: Shebang should be #!/usr/bin/python2 or #!/usr/bin/python3 (bad-shebang)
C:  1, 0: Modules should have docstrings (even a one liner) (module-missing-docstring)
C: 11, 0: Classes should have docstrings (even a one liner) (class-missing-docstring)
C: 17, 2: Second line should be blank (docstring-second-line-blank)
C: 23, 2: Second line should be blank (docstring-second-line-blank)
C: 30, 0: Classes should have docstrings (even a one liner) (class-missing-docstring)
C: 37, 0: Classes should have docstrings (even a one liner) (class-missing-docstring)
W: 69,31: Redefining built-in 'input' (redefined-builtin)
W:187, 4: Redefining built-in 'input' (redefined-builtin)
W:200, 4: Redefining built-in 'input' (redefined-builtin)
W:213, 4: Redefining built-in 'input' (redefined-builtin)
W:270, 4: Redefining built-in 'input' (redefined-builtin)
C:233, 2: Trailing whitespace in docstring: offset:33: {} (docstring-trailing-whitespace)
R:  1, 0: Missing "from __future__ import print_function" line (missing-print-function)

toolchain-utils/crosperf/experiment.py
************* Module experiment
W: 86,35: Access to a protected member _all_machines of a client class (protected-access)
W: 93,21: map/filter on lambda could be replaced by comprehension (deprecated-lambda)
W:181,10: Redefining name 'benchmark_run' from outer scope (line 17) (redefined-outer-name)
W:188, 8: Redefining name 'benchmark_run' from outer scope (line 17) (redefined-outer-name)
W:180, 6: Attribute 'active_threads' defined outside __init__ (attribute-defined-outside-init)