Add exclusion to org.sonatype.aether/aether-connector-wagon

Exclude [org.codehaus.plexus/plexus-utils "2.0.7"] based on report
generated by lein deps :tree

[com.cemerick/pomegranate "0.2.0"] -> [org.sonatype.aether/aether-connector-wagon "1.13.1"] -> [org.codehaus.plexus/plexus-utils "2.0.7"]
 overrides
[com.cemerick/pomegranate "0.2.0"] -> [org.apache.maven.wagon/wagon-provider-api "2.2"] -> [org.codehaus.plexus/plexus-utils "3.0"]
 and
[com.cemerick/pomegranate "0.2.0"] -> [org.apache.maven.wagon/wagon-http "2.2"] -> [org.apache.maven.wagon/wagon-provider-api "2.2"] -> [org.codehaus.plexus/plexus-utils "3.0"]
 and
[com.cemerick/pomegranate "0.2.0"] -> [org.apache.maven.wagon/wagon-http "2.2"] -> [org.apache.maven.wagon/wagon-http-shared4 "2.2"] -> [org.apache.maven.wagon/wagon-provider-api "2.2"] -> [org.codehaus.plexus/plexus-utils "3.0"]
Merge pull request #64 from vedang/master

Add old plexus-utils exclusion to org.sonatype.aether/aether-connector-wagon
Fixed #61: resolve-artifacts* type error when using a :files map

resolve-artifacts* accepts a map of known artifacts to file names but treats them as dependencies instead of artifacts. This causes a type error at runtime if a :files map is actually provided. This patch corrects the error (likely from copy-paste, see #61) and adds a test for resolving artifacts against a :files map.
Merge pull request #66 from montoux/type-error-in-resolve-artifacts

Fixed #61: resolve-artifacts* type error when using a :files map