Include Gometalinter in Travis CI build

[vaskoz]

Fixes #50

Checklist

• I have made a material change to the repo (functionality, testing, spelling, grammar)
• I have read the [Contribution Guide] and my PR follows them.
• I updated my branch with the master branch.
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation about the functionality in the appropriate .md file
• I have added in line documentation to the code I modified

Short description of what this PR does:

• Added the gometalinter to the TravisCI build
• Enabled all linters with the exception of golint because golint is suggesting a change to an exported type which will break the public API.
• Invoked gometalinter on ./....

At some point, the golint issues should also be fixed and the --disable=golint should be removed from .travis.yml

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[thinkingserious]

Hello @vaskoz,

Thanks again for the PR!

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