Fix Travis build broken by last merge.

Two problems:

  1. GOBIN was not in PATH.
  2. Decryption key was not set.
$ export PATH=$HOME/gopath/bin:$PATH
$ export KEY_PASSWORD=[secure]
git.1
$ git clone --depth=50 --branch=namn/test-travis git://github.com/googlegenomics/api-client-go.git googlegenomics/api-client-go
Cloning into 'googlegenomics/api-client-go'...
remote: Counting objects: 100, done.
remote: Compressing objects: 100% (64/64), done.
remote: Total 100 (delta 43), reused 80 (delta 35)
Receiving objects: 100% (100/100), 40.11 KiB | 0 bytes/s, done.
Resolving deltas: 100% (43/43), done.
Checking connectivity... done.
$ cd googlegenomics/api-client-go
git.3
$ git checkout -qf 6f412261e2526410c495a1c6069087c6ee056b7e
gvm.get
$ gvm get
Your branch is up-to-date with 'origin/master'.
remote: Counting objects: 75, done.
remote: Compressing objects: 100% (59/59), done.
remote: Total 75 (delta 23), reused 38 (delta 13)
Unpacking objects: 100% (75/75), done.
From https://github.com/moovweb/gvm
   bc2b638..d108d7d  master     -> origin/master
 * [new branch]      lots_of_tests -> origin/lots_of_tests
Updating bc2b638..d108d7d
Fast-forward
 README                              |  2 +-
 README.md                           |  2 +-
 bin/gvm                             |  6 +++-
 binscripts/gvm-installer            |  6 ++--
 scripts/alias                       |  4 +--
 scripts/alias-create                | 10 +++---
 scripts/alias-delete                |  8 ++---
 scripts/alias-list                  |  4 +--
 scripts/cross                       | 12 +++----
 scripts/diff                        |  6 ++--
 scripts/env/gvm                     | 27 +++++++-------
 scripts/env/implode                 | 11 ++++++
 scripts/env/pkgset-use              |  8 ++---
 scripts/env/use                     |  8 ++---
 scripts/function/gvm_export_path    |  2 +-
 scripts/function/tools              |  8 ++---
 scripts/functions                   |  2 +-
 scripts/get                         | 19 +++++-----
 scripts/gvm-default                 | 16 ++++-----
 scripts/install                     | 71 +++++++++++++++++++------------------
 scripts/linkthis                    |  4 +--
 scripts/list                        |  6 ++--
 scripts/listall                     |  8 ++---
 scripts/pkgset                      |  4 +--
 scripts/pkgset-create               | 14 ++++----
 scripts/pkgset-delete               |  6 ++--
 scripts/pkgset-empty                |  4 +--
 scripts/pkgset-list                 |  4 +--
 scripts/templates/binary            | 10 +++---
 scripts/uninstall                   | 10 +++---
 scripts/update                      |  7 ++--
 tests/zzgvm_implode_comment_test.sh |  3 ++
 32 files changed, 164 insertions(+), 148 deletions(-)
 create mode 100644 scripts/env/implode
 create mode 100644 tests/zzgvm_implode_comment_test.sh
gvm.update
$ gvm update && source $HOME/.gvm/scripts/gvm
pulling from https://go.googlecode.com/hg/
searching for changes
adding changesets
adding manifests
adding file changes
added 479 changesets with 1114 changes to 584 files (+1 heads)
(run 'hg heads' to see heads)
gvm.install
$ gvm install go1.2
Already installed!
$ gvm use go1.2
Now using version go1.2
$ export GOPATH=$HOME/gopath:$GOPATH

The above is copied from Travis build log. There are two problems:

1. GOPATH is set __after__ whatever envvar we have in the config.
2. GOPATH is set as $HOME/gopath:$GOPATH. If GOPATH is initially empty or undefined, the final GOPATH will have ":" at the end. So PATH=$GOPATH/bin is translated to PATH=$HOME/gopath:/bin, which is wrong.