Rewrite a subscription test

Rewrite method `test_negative_create_1` in module
`tests.foreman.api.test_subscription`. The test docstring states that it should
not be possible to upload the same manifest to two organizations, but the actual
test code did not verify this assertion. Make that happen.

    $ nosetests tests/foreman/api/test_subscription.py -m test_negative_create_1
    .
    ----------------------------------------------------------------------
    Ran 1 test in 31.106s

    OK
Add basic installer test

Add InstallerTestCase which provides a virtual machine for installing
the system.

Update requirements.txt to include automation-tools.

Add test_basic_installer module with a simple test case as prototype for
future installer tests.
Merge pull request #1780 from elyezer/installer-tests

Add basic installer test
Add CLI test for activation-key copy
Adresses #1704

Test results
------------
@Test: Copy Activation key for all valid Activation Key name ... ok
@Test: Copy Activation key for all valid Activation Key name ... ok
@Test: Copy Activation key for all valid Activation Key name ... ok
@Test: Copy Activation key for all valid Activation Key name ... ok
@Test: Copy Activation key for all valid Activation Key name ... ok
@Test: Copy Activation key for all valid Activation Key name ... ok

Added second test to copy an activation key by its name
Results
-------
@Test: Copy Activation key by passing name of parent ... ok
Merge pull request #1786 from JacobCallahan/master

Add CLI test for activation-key copy
Merge pull request #1781 from Ichimonji10/test-subscription

Rewrite a subscription test
Improve CLI search method

Better handle unicode search values. Also escape double quotes in order
to correctly handle searching tags values.
Merge pull request #1787 from elyezer/improve-cli-search

Improve CLI search method
Fix cli Base.search docstring typo

The Base.search method docstring was updated but a typo passed in the PR
review. Fix that.
Merge pull request #1788 from elyezer/docstring-typo

Fix cli Base.search docstring typo