remove indirect dependecy on textmapper

The textmapper dependecy is tracked by the llir/ll repo.
Most likely, we ended up with tracking the specific version
of the transitive dependency of textmapper when using
`go get -u` to update.

For future updates, we may want to use e.g.
`go get github.com/pkg/errors@latest` instead.

Author: mewmew

go.mod

@@ -1,7 +1,6 @@
 module github.com/llir/llvm
 
 require (
-	github.com/inspirer/textmapper v0.0.0-20190101225825-ae0b38e27780 // indirect
 	github.com/kr/pretty v0.1.0
 	github.com/llir/ll v0.0.0-20190101214934-d9b443a40870
 	github.com/mewkiz/pkg v0.0.0-20181231041609-5720a0c5985d

go.sum

@@ -1,7 +1,5 @@
 github.com/inspirer/textmapper v0.0.0-20181224220124-bad2c4921a6b h1:NUCmRA9SMqaR9ePibBcE7Qakv81krZarfGg1XNVcQOs=
 github.com/inspirer/textmapper v0.0.0-20181224220124-bad2c4921a6b/go.mod h1:SpoIwXu07A3gguovN379QUCTHpUk1lhX2KIjVxpQOas=
-github.com/inspirer/textmapper v0.0.0-20190101225825-ae0b38e27780 h1:pw08V8HYitrJVu78g/A0qeKP4n88/z/4xryA3i6NY58=
-github.com/inspirer/textmapper v0.0.0-20190101225825-ae0b38e27780/go.mod h1:SpoIwXu07A3gguovN379QUCTHpUk1lhX2KIjVxpQOas=
 github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=