appc: bump version of spec to 0.7.4

[cgonyeo]

Addresses at least part of: #98

Would probably want to use a tagged release of rkt also to consider the issue fully addressed.

[jonboulle]

What version of godep are you using? there're a whole bunch of license files that shouldn't be getting dragged in:

 Godeps/_workspace/src/github.com/camlistore/camlistore/third_party/bazil.org/fuse/LICENSE
+176 −0  Godeps/_workspace/src/github.com/camlistore/camlistore/third_party/closure/lib/LICENSE
+27 −0  Godeps/_workspace/src/github.com/camlistore/camlistore/third_party/code.google.com/p/goauth2/LICENSE
+22 −0  Godeps/_workspace/src/github.com/camlistore/camlistore/third_party/code.google.com/p/goauth2/PATENTS
+27 −0  .../_workspace/src/github.com/camlistore/camlistore/third_party/code.google.com/p/leveldb-go/LICENSE
+27 −0  ...s/_workspace/src/github.com/camlistore/camlistore/third_party/code.google.com/p/snappy-go/LICENSE
+202 −0  ...s/_workspace/src/github.com/camlistore/camlistore/third_party/code.google.com/p/xsrftoken/COPYING
+4 −0  Godeps/_workspace/src/github.com/camlistore/camlistore/third_party/fontawesome/LICENSE.txt
+202 −0  ...ps/_workspace/src/github.com/camlistore/camlistore/third_party/github.com/camlistore/lock/COPYING
+27 −0 

etc etc