Use IsText for testing Text objects

[andreoss]

• Avoid calling asString
  Releated to TextIs should test asString(), toString(), equals() and hashCode() llorllale/cactoos-matchers#199

[0crat]

@victornoel/z everybody who has role REV is banned at #1604; I won't be able to assign anyone automatically; consider assigning someone manually (as in §19), or invite more people (as in §51), or remove the job from the scope (as in §14)

[victornoel]

@andreoss thx, there were some strange things in there that you simplified :D

[victornoel]

@rultor merge

[rultor]

@rultor merge

@victornoel OK, I'll try to merge now. You can check the progress of the merge here

[rultor]

@rultor merge

@victornoel Done! FYI, the full log is here (took me 11min)

[0crat]

Job gh:yegor256/cactoos#1604 is not assigned, can't get performer