ruby 2.7 warnings

[zenspider]

Tons of warnings coming up when I test our gem against ruby 2.7:

.../strings-0.1.7/lib/strings.rb:19: warning: The last argument is used as the keyword parameter
.../strings-0.1.7/lib/strings/align.rb:39: warning: for `align' defined here
.../strings-0.1.7/lib/strings/align.rb:42: warning: The last argument is used as the keyword parameter
.../strings-0.1.7/lib/strings/align.rb:85: warning: for `align_center' defined here
.../strings-0.1.7/lib/strings.rb:19: warning: The last argument is used as the keyword parameter
.../strings-0.1.7/lib/strings/align.rb:39: warning: for `align' defined here
.../strings-0.1.7/lib/strings/align.rb:42: warning: The last argument is used as the keyword parameter
.../strings-0.1.7/lib/strings/align.rb:85: warning: for `align_center' defined here

probably more, with the output above limited by our usage of the gem.

[zenspider]

I figured out that I named the travis setup wrong... it should be 2.7.0-preview2.

[piotrmurach]

Released new version 0.1.8 with your fix.