Skip subject line length check for merge commits

Some merge requests (e.g. those created for release branches) include
merge commits.  Prevent Danger from warning about excessive subject line
length for merge commits.  (While the proper way to detect a merge
commit would be to check the 'parents' attribute of a commit object,
Danger Python does not seem to populate that attribute, so a simple
string search is performed on the commit subject instead.)
76 jobs for !4503 with michal/improve-danger-checks in 11 minutes and 5 seconds (queued for 7 seconds)
detached
Status Job ID Name Coverage
  Autoconf
passed #1411790
linux amd64
autoreconf

00:00:17

 
  Precheck
passed #1411792
linux amd64
clang-format

00:00:17

passed #1411793
linux amd64
coccinelle

00:03:33

passed #1411794
linux amd64
danger

00:00:16

passed #1411791
linux amd64
misc

00:00:19

passed #1411795
linux amd64
tarball-create

00:01:47

 
  Build
passed #1411808
linux amd64
clang:asan

00:02:07

passed #1411812
linux amd64
clang:buster:amd64

00:01:16

passed #1411815
amd64 libvirt
clang:freebsd11:amd64

00:01:16

passed #1411816
amd64 libvirt
clang:freebsd12:amd64

00:01:10

passed #1411817
amd64 libvirt
clang:openbsd:amd64

00:02:24

passed #1411810
linux amd64
clang:tsan

00:01:05

passed #1411796
linux amd64
gcc:alpine3.12:amd64

00:01:00

passed #1411807
linux amd64
gcc:asan

00:01:50

passed #1411800
linux amd64
gcc:buster:amd64

00:00:51

passed #1411797
linux amd64
gcc:centos7:amd64

00:00:57

passed #1411798
linux amd64
gcc:centos8:amd64

00:01:14

passed #1411806
linux amd64
gcc:focal:amd64

00:00:59

passed #1411811
linux amd64
gcc:mutexatomics

00:00:56

passed #1411802
linux amd64
gcc:out-of-tree

00:01:00

passed #1411801
linux amd64
gcc:sid:amd64

00:01:21

passed #1411803
linux i386
gcc:sid:i386

00:00:51

passed #1411813
linux amd64
gcc:softhsm2.4

00:00:57

passed #1411814
linux amd64
gcc:softhsm2.6

00:01:03

passed #1411799
linux amd64
gcc:stretch:amd64

00:01:09

passed #1411809
linux amd64
gcc:tsan

00:01:06

passed #1411804
linux amd64
gcc:tumbleweed:amd64

00:00:47

passed #1411805
linux amd64
gcc:xenial:amd64

00:01:03

passed #1411818
amd64 windows
msvc:windows:amd64

00:00:45

 
  Unit
passed #1411830
linux amd64
unit:clang:asan

00:01:26

passed #1411834
linux amd64
unit:clang:buster:amd64

00:01:05

passed #1411837
amd64 libvirt
unit:clang:freebsd11:amd64

00:01:29

passed #1411838
amd64 libvirt
unit:clang:freebsd12:amd64

00:01:29

passed #1411839
amd64 libvirt
unit:clang:openbsd:amd64

00:02:52

passed #1411832
linux amd64
unit:clang:tsan

00:03:09

passed #1411819
linux amd64
unit:gcc:alpine3.12:amd64

00:01:18

passed #1411829
linux amd64
unit:gcc:asan

00:01:26

passed #1411823
linux amd64
unit:gcc:buster:amd64

00:02:12

passed #1411820
linux amd64
unit:gcc:centos7:amd64

00:01:12

passed #1411821
linux amd64
unit:gcc:centos8:amd64

00:01:10

passed #1411828
linux amd64
unit:gcc:focal:amd64

00:01:16

passed #1411833
linux amd64
unit:gcc:mutexatomics

00:01:12

passed #1411824
linux amd64
unit:gcc:sid:amd64

00:01:05

passed #1411825
linux i386
unit:gcc:sid:i386

00:01:10

passed #1411835
linux amd64
unit:gcc:softhsm2.4

00:01:08

passed #1411836
linux amd64
unit:gcc:softhsm2.6

00:01:10

passed #1411822
linux amd64
unit:gcc:stretch:amd64

00:01:14

passed #1411831
linux amd64
unit:gcc:tsan

00:04:00

passed #1411826
linux amd64
unit:gcc:tumbleweed:amd64

00:01:09

passed #1411827
linux amd64
unit:gcc:xenial:amd64

00:01:13

 
  System
canceled #1411851
linux amd64
system:clang:asan

00:08:26

canceled #1411855
linux amd64
system:clang:buster:amd64

00:08:24

canceled #1411858
amd64 libvirt
system:clang:freebsd11:amd64

00:09:24

canceled #1411859
amd64 libvirt
system:clang:freebsd12:amd64

00:08:58

canceled #1411853
linux amd64 allowed to fail
system:clang:tsan

00:09:22

canceled #1411840
linux amd64
system:gcc:alpine3.12:amd64

00:09:43

canceled #1411850
linux amd64
system:gcc:asan

00:08:33

canceled #1411844
linux amd64
system:gcc:buster:amd64

00:07:38

canceled #1411841
linux amd64
system:gcc:centos7:amd64

00:09:42

canceled #1411842
linux amd64
system:gcc:centos8:amd64

00:09:26

canceled #1411849
linux amd64
system:gcc:focal:amd64

00:09:39

canceled #1411854
linux amd64
system:gcc:mutexatomics

00:09:40

canceled #1411845
linux amd64
system:gcc:sid:amd64

00:08:34

canceled #1411846
linux i386
system:gcc:sid:i386

00:09:51

canceled #1411856
linux amd64
system:gcc:softhsm2.4

00:09:42

canceled #1411857
linux amd64
system:gcc:softhsm2.6

00:09:35

canceled #1411843
linux amd64
system:gcc:stretch:amd64

00:09:32

canceled #1411852
linux amd64 allowed to fail
system:gcc:tsan

00:09:31

canceled #1411847
linux amd64
system:gcc:tumbleweed:amd64

00:09:52

canceled #1411848
linux amd64
system:gcc:xenial:amd64

00:09:36

 
  Docs
passed #1411860
linux amd64
docs

00:01:12

 
  Postcheck
passed #1411864
linux amd64
cppcheck

00:00:45

passed #1411861
linux amd64
flake8

00:00:25

canceled #1411865
linux amd64
gcov

passed #1411862
linux amd64
pylint

00:00:23

passed #1411863
linux amd64
scan-build

00:04:25