Relicense psm from ISC/Apache-2.0 to MIT/Apache-2.0

The ISC and MIT licenses are equivalent, however the ISC license is not
white-listed for use in the rustc compiler, whereas the MIT one is.

As I’m the sole author of psm, no third parties need to be involved in
the decision to execute the re-license.

Author: nagisa

psm/Cargo.toml

@@ -1,13 +1,13 @@
 [package]
 name = "psm"
-version = "0.1.6"
+version = "0.1.7"
 authors = ["Simonas Kazlauskas <[email protected]>"]
 build = "build.rs"
 description = "Portable Stack Manipulation: stack manipulation and introspection routines"
 keywords = ["stack", "no_std"]
-license = "ISC/Apache-2.0"
+license = "MIT/Apache-2.0"
 repository = "https://github.com/rust-lang/stacker/"
-documentation = "https://docs.rs/psm/0.1.6"
+documentation = "https://docs.rs/psm/0.1.7"
 readme = "README.mkd"
 
 [dependencies]