Drop php EOL versions

[dxops]

Test agains actual phpunit versions

[scrutinizer-notifier]

The inspection completed: No new issues

[gavinlove]

Thanks for the contribution, I was unsure about cutting off support for EOL versions without any changes in features that would require it but I think this is ok.

[dxops]

I was unsure too, but I think we can move forward according to EOL versions usage for now.

For 5.5 features I suggest to move to AST from reflection somehow, will try POC shortly. Reflection often causes segfaults on our large test suite

(gdb) bt
#0  zend_mm_alloc_small (bin_num=<optimized out>, heap=<optimized out>, size=<optimized out>) at /tmp/php-build/source/7.0.13/Zend/zend_alloc.c:1295
#1  _emalloc_56 () at /tmp/php-build/source/7.0.13/Zend/zend_alloc.c:2369
#2  0x00000000009495b2 in ZEND_INIT_ARRAY_SPEC_CV_UNUSED_HANDLER (execute_data=0x7fffee01c1a0) at /tmp/php-build/source/7.0.13/Zend/zend_vm_execute.h:35034
#3  0x00000000009152a0 in execute_ex (ex=<optimized out>) at /tmp/php-build/source/7.0.13/Zend/zend_vm_execute.h:417
#4  0x00000000008c2ea0 in zend_call_function (fci=0x7fffffff9bf0, fci_cache=0x7fffffff9c40) at /tmp/php-build/source/7.0.13/Zend/zend_execute_API.c:858
#5  0x000000000071413b in zim_reflection_method_invokeArgs (execute_data=<optimized out>, return_value=0x7fffee019d20) at /tmp/php-build/source/7.0.13/ext/reflection/php_reflection.c:3346
#6  0x000000000095de47 in ZEND_DO_FCALL_SPEC_HANDLER (execute_data=0x7fffee019b50) at /tmp/php-build/source/7.0.13/Zend/zend_vm_execute.h:842
#7  0x00000000009152a0 in execute_ex (ex=<optimized out>) at /tmp/php-build/source/7.0.13/Zend/zend_vm_execute.h:417
#8  0x000000000096d967 in zend_execute (op_array=<optimized out>, return_value=<optimized out>) at /tmp/php-build/source/7.0.13/Zend/zend_vm_execute.h:458
#9  0x00000000008d27a4 in zend_execute_scripts (type=8, retval=0x0, file_count=3) at /tmp/php-build/source/7.0.13/Zend/zend.c:1427
#10 0x0000000000865576 in php_execute_script (primary_file=0x7fffffffc1c0) at /tmp/php-build/source/7.0.13/main/main.c:2494
#11 0x000000000096f6ce in do_cli (argc=7, argv=0x12740d0) at /tmp/php-build/source/7.0.13/sapi/cli/php_cli.c:974
#12 0x00000000004545f5 in main (argc=7, argv=0x12740d0) at /tmp/php-build/source/7.0.13/sapi/cli/php_cli.c:1344
(gdb) 

As for 4.x PHPUnit versions, I suggest not to drop it until 2017