Fixed updates for non-timed progressbars. Fixes wolph#185

Merge tag 'v3.39.1' into develop

added support for dirty progressbar thanks to @ritze v3.39.1

# gpg: Signature made Mon Dec 17 01:49:58 2018 CET
# gpg:                using RSA key 149325FD15904E9C4EB89E95E81444E9CE1F695D
# gpg: Good signature from "Rick van Hattem <[email protected]>" [ultimate]
# gpg:                 aka "[jpeg image of size 9662]" [ultimate]

Merge tag 'v3.39.0' into develop

Added python 3.7 and armv6 test support and fixed stdout/stderr wrapping thanks to @ikonst v3.39.0

# gpg: Signature made Sun Dec 16 04:27:36 2018 CET
# gpg:                using RSA key 149325FD15904E9C4EB89E95E81444E9CE1F695D
# gpg: Good signature from "Rick van Hattem <[email protected]>" [ultimate]
# gpg:                 aka "[jpeg image of size 9662]" [ultimate]

postpone travis python 3.7 support until its supported natively

added prefix/suffix arguments to fix wolph#168

making sure we run all the finish code. fixes wolph#162

improved tests

added tests to prevent problems like wolph#157

extended samples tests

fixed bug wolph#154 "Progress bar display does not update", again...