v0.4.2 Bugfixes

bug fixes for DTM constructor and for remove_patterns (#94)

* Fixes case where DocumentTermMatrix(crps, lex) would construct a dtm of wrong dimensions if a term provided in lex does not occur in the crps

* added DocumentTermMatrix constructor that takes a crps and a prespecified terms vector

* fixed remove_patterns to use nextind() to find starting position of next unstripped substring. Closes #92

* removed leftover info() statement in prepare! test